Hirschsprung Disease Part 2

Welcome to Stay Current in Pediatric Surgery. Today's podcast is a continuation on the previous episode on Hirschsprung's disease with Dr. Mark Levitt. But before we get into today's podcast, here are some highlights from our previous episode on pediatric trauma with Dr. Richard Falcone. Previously on Stay Current. Rich, can you take us through the standards of care for C-spine management? The ultimate risk of injury is actually pretty low. And C-collar is often a useful adjunct that gives you time. Okay, so I would like to repeat this because I think this is an important point. If they have any tenderness at all, or you don't think you could trust your exam, then you get an AP in lateral film to make sure there's no bony injuries. And going along with that theme you said before, keep them in the collar and re-examine them the next day. And that the only time you should be getting a CAT scan if there are hard signs of a spinal cord injury or any neurologic spinal deficits. Is that right? Correct. In a child with a head injury, how do you decide when to work them up for non-accidental trauma? And your mechanism was something that was not witnessed publicly. We get skeletal survey and get our social worker to evaluate the family. Rich, what's the role of angiography for solid organ injury in children? And I think there's no good evidence. And in those small kids, you actually may be putting them at more risk of an injury from angioing them or from knocking out most of their spleen anyway and losing any benefit of not doing the splenectomy in the first place. Stay Current is an audio publication designed to keep healthcare professionals up to date with standards of care and new emerging ideas. These podcasts are designed to keep healthcare professionals current while on their commute. Stay Current is created and edited by Todd Ponsky and Nicholas Bruns in partnership with GlobalCastMD and is recorded and produced at Akron Children's Hospital in Akron, Ohio. Well, we are back here today with Stay Current, this time discussing Hirsprungs again, but going into more complex, difficult issues that we didn't really address the first time we discussed Hirsprungs. And again, we're with Dr. Mark Levitt, who's at Nationwide Children's Hospital. Mark, thanks for joining us. My pleasure. Great to be back. Let's start off now, Mark, and get into some of the more challenging stuff, which I know you deal a lot with. And let's start off with a two-year-old who has Hirsprungs disease and who has had a previous suave pull-through done in the newborn period. And now he's presenting about two years later with three episodes over the past six months of enterocolitis. So he's had three episodes of enterocolitis over the past six months. Each time he's had these episodes of enterocolitis, he's been admitted to the hospital. So the family comes to you, what do they do? They're getting frustrated with this. What are the post-pull-through problems that you've encountered in your experience? So the vast majority of patients with Hirsprungs disease do extremely well, and they have no problem with emptying, and they stool normally and have normal bowel control. The problem patients, I really divide into two types. One is the obstruction patient, the patient that does not empty, and then the other is the soiling patient. Occasionally, there's some mixing, but essentially those are distinct types. And the case that you're describing is a child whose pull-through is not successfully emptying, leading to stasis, distension, and of course, enterocolitis. And the evaluation of that patient is something worth discussing because it faces pediatric surgeons and gastroenterologists on a regular basis. All right. So let's go through that. So how do you evaluate the post-pull-through patient who's presenting with obstructive symptoms? So I like to know the timing. So a patient has enterocolitis after a well-done pull-through is not something uncommon. That happens a lot, and particularly if they are babies. And I think the etiology for that is that babies have very tight sphincters, and they're capable of keeping their sphincters tight for many, many hours, and that can lead them to enterocolitis. So even a perfectly done pull-through patient can have enterocolitis in the postoperative period. We all know that, and it's treated appropriately with irrigations and IV fluids and antibiotics. However, after about the age of one, the patients really should learn how to empty and relax their sphincters and have sort of a more normal bowel movement pattern. And if they don't have that because they can't empty, and they have such a problem emptying that they develop enterocolitis, that child needs an evaluation. So that evaluation in my book involves a contrast study of the colon and an examination under anesthesia. All right, Mark, can you give us the bullet points of, give us the list of what are some of the anatomic things that can go wrong? So the pull-through itself could have a distal stricture, and obviously that is a stenotic area that will not allow for emptying and can lead to backup and enterocolitis. Then the patient might have an obstructing cuff. And this is something I think people don't know a lot about because most surgeons are doing suaves. And as we talked about on the last podcast, the suave cuff has been getting shorter and shorter. But if the cuff either wasn't properly split or has fused or has scarred down in some way, that aganglionic extra or the outer rectal wall can cause obstruction. So I would say that would be the next common cause of an obstruction. Then I would say the Duhamel pouch, a Duhamel pouch that is atonic and not working well. They're by definition atonic, but if they're too big, or if the ganglionated bowel connecting to them is too weak, that can cause obstruction. The pull-through itself can be twisted, can even be twisted 360 degrees, that can lead to an obstruction. So all of those that I've just described are anatomic. The one other one that not uncommonly happens is just a dilated segment. And it's hard to know whether that dilated up over time or if that was the dilated segment that was left behind at the original pull-through. But a big, boggy distal pull-through can also lead to stasis. So the other side, the other cause of trouble, in addition to anatomy, is pathology. So if the pull-through was done well, but was not done to a good segment of ganglionated and normal-sized nerve bowel, then they can be obstructed on those grounds. And I want to restate what you taught me last time, is that to try to mitigate the chances of that happening, you like your pathologist to tell you that the nerve roots are no bigger than 40 microns. Is that correct? That's correct. So you want to confirm that you have healthy ganglion cells and you have 40 or less micron-sized nerves in the pull-through segment. Anything larger than that, I would consider transition zone bowel that might not function. Okay. Mark, can you go through how you deal with patients that come in with enterocolitis after they've had a pull-through? What is your treatment protocol for those patients? So a patient that presents after their pull-through with enterocolitis is a fairly common scenario, and it doesn't mean that anything poorly was done about the pull-through. It just happens. And I think it happens because the babies have particularly tight sphincters. You have to make sure, of course, that there's no stricture. And I would examine the pull-through with Hagar dilators, not my finger, particularly in a baby, and make sure that there's no narrowing. But if it feels good and the anastomosis feels good and they still have enterocolitis, that patient needs hydration and intravenous flagyl etronidazole, and then needs irrigations. And obviously, that first passage of the irrigation tube needs to be done by someone who understands the surgery and can gently insert it. Usually, that slides in very smoothly, particularly after three or four weeks following the surgery. And then the parents can learn how to do that from the nurses as the patient gets better from their enterocolitis. So that would be my treatment protocol is to give them intravenous fluids, intravenous antibiotics. Metronidazole seems to be the most effective. And aggressive irrigations two or three times a day. And about 10 cc's per kilo? Yeah. So you can give 10 to 20 cc's into a large foley, like a size 20 to 22 foley. Mm-hmm. And then let it drip out. And then put it in another 10 to 20 cc's and let it drip out. And move the tube so that you're essentially washing the inside of that colon. So you need to relieve the distension. And it should be a gratifying experience. And you should feel like you're making the baby better. And if you're not succeeding in doing that, then you're either not doing the irrigations correctly or the tube is not getting in high enough. Maybe it's not able to reach that high. And that's the patient that might be particularly ill that you can't get better with irrigations that may need a ileostomy. Yeah. And I want to direct the listeners to the previous podcast where we went into more detail on the technique for rectal irrigations. And this is the same. Why not use oral flagyl or oral vancomycin or even rectal antibiotics? Actually, flagyl, given in the irrigant, does work. But of course, then most of it gets irrigated out. Oral flagyl works with the same efficacy as intravenous flagyl. But usually the child isn't interested in eating much or is even maybe vomiting. And flagyl is pretty nauseating. So if the child is able to eat and is doing better in the improvement phase of the enterocolitis, of course, you can transition them to oral metrodinazole. Okay. Yeah. I always thought that the... I don't know for sure, but I always thought that the IV flagyl only had 30% efficacy as the oral because you had to wait for biliary excretion. But I actually don't know that that's true. So it's... Well, actually, what's interesting about flagyl is it has the same efficacy, IV or PO, because in both cases, it is excreted in the bile. Right. Which is very relevant. So if you have a patient, for example, that has colitis from, let's say, from C. difficile, slightly off topic, in the colon, and it's a colon that's diverted with an ileostomy, flagyl will not work in that situation because you're not getting any of the flagyl into the colon. Right. It's coming out the ileostomy. Right. In that patient, you need to give enemas with vancomycin. Mm-hmm. Okay. So back to the patient, you just explained, basically, the bullet points that there are in these patients that have recurrent episodes of enterocolitis that last for more than, you know, I guess, let me ask you, what would be the normal expected period of episodes of enterocolitis? So I think, you know, a patient can have maybe 15% to 20% of patients after pull-through, is what the literature would say, can actually have an episode of enterocolitis within the first year after their pull-through. But I believe that after a year, they probably ought not to be having enterocolitis anymore. And if they are, it's really your obligation to seek an anatomic or pathologic explanation for that. And to reiterate that, you take these patients, you'll do a contrast study, and then you'll take them to the operating room for an examination under anesthesia. Yeah. So let's go through what we look for in the contrast study first, and then we should talk about what we look for on the examination under anesthesia. Perfect. So on the contrast study, we are looking for the anatomic causes that I've enumerated. You should be able to see a cuff. You can see an indentation. I particularly focus on the presacral space. The pull-through ought to hug the sacrum, and sometimes it's sort of diverted forward by some space-occupying mass, which ultimately turns out to be a cuff. You should be able to feel that on digital exam as well. And I want to make sure we're very clear here in the words we're using. So when you say you should be feeling it, you mean if it's a problem, if it's there, you would feel it. In a normal, correctly performed operation, you would not be feeling it. Is that correct? Yes. I would say that's correct, and particularly in a problematic patient, that that may be the explanation. You may see an indentation of the pull-through on its posterior aspect in the presacral space. And in addition, you can often feel that on digital rectal exam under anesthesia. And that is something that a lot of clinicians don't know about. As I said, most surgeons out there are doing Suave, but as we spoke about on the last podcast, I believe that those Suaves are becoming more Swenson-like, and I think there are more and more Swenson enthusiasts. But the Suave long cuff situation, and there are thousands of children walking around with that anatomy, if that patient's doing well, great. If that patient is not doing well, it may be the cuff. Because by definition, the outer wall of the rectum is still there, and it's, of course, aganglionic, and it sets up what I consider a physiologic obstruction. You can see that on the contrast study. Okay. The contrast study, of course, can also show a stricture with a dilated segment above. The contrast study could show a twist of the pull-through. That you got to look for. The radiologist has to be fairly savvy and note that there's sort of a narrowing on, even in the oblique, and it's on every single image and doesn't distend. The contrast study can show a large Duhamel pouch, and the contrast study could show a dilated distal segment, which is another possible cause of things not moving through. Is there a special way when they're doing the contrast study, because I imagine it may be difficult to see evidence of that cuff and denting if they're putting the catheter in past that point. Do you look for it on the emptying part of the exam? Yeah, exactly. You need to be savvy about removing that tube and let them empty, and you make sure you have a good lateral view. I always look at the lateral view. Okay. Good. Good tip. Okay. So for the examination under anesthesia, I obviously, we anesthetize the patient. I put the Lone Star retractor on the anus at the skin level, and I inspect for several things. First, before I do that, I do a digital exam and feel if I can feel a cuff, if I can feel a stricture, if I can feel a spur in a Duhamel. I didn't mention that before, but that's something you need to know, is the Duhamel wasn't well mated into two, making two lumens into one. There may be a spur between the two lumens that can cause obstruction. And I want to inspect the dentate line. I want to see if the dentate line is intact. This is relevant for our discussion about continence, because that's an important area of anal canal sensation. So we talked about stricture. We talked about cuff. The cuff, by the way, I will use my fifth digit, and I will feel along the hollow of the sacrum. And you feel this rubbery, sort of thick rubber band structure that goes around the pull-through, outside of the pull-through. And it's really important to get good at feeling that. A lot of people have done rectal exams on patients that I have seen and said it was normal. And then I put my finger in and I feel a very obvious cuff. So you got to put in your mind's eye what is outside of the pull-through. And this is really important, particularly for gastroenterologists who are used to visualizing colons intraluminally with scopes. This is not something you'd ever detect intraluminally. It's outside of the pull-through. You can't really feel a twist on exam. It's mostly a contrast study issue. And then we take a biopsy and make sure that biopsy is above the dentate line by about a centimeter to make sure that the pull-through segment was done with good ganglion cells and with normal-sized nerves. And because this diagnosis is so critical, we will send it for permanent section. I don't depend on frozen for this redo situation. And I want my pathologist to tell me about the quality of the nerves and whether or not the quality of nerves as far as their size and whether, of course, there are ganglion cells present. Okay. What about in this patient you go in and you find, let's say that there's, let's take the different situations. You find that the, let's say that there are some ganglion cells, but there are hypertrophic nerves. That is a transition zone pull-through. And how do you manage that? If that patient is not doing well, which is why they came for this evaluation, they need a redo of their pull-through in my opinion. Okay. And I would approach that prone and supine, transanal dissection, preservation of the anal canal and dentate line, and a full thickness dissection of the actual pull-through itself, and removal of the cuff, because then it's pretty easy to see once the pull-through has been dissected. And you got to get down to good ganglionated bowel. So that may require an additional laparotomy or laparoscopy for mobilization to get to a good level. Oftentimes, it's a patient who much of the sigmoid curve was not removed. We talked about that the last time. And if you remove the sigmoid and sort of straighten it, then you get to healthy bowel. Any tips for, with the transanal dissection, getting into the correct plane on a redo? It's a little trickier, but you basically want to hug the bowel. You want to get into the Swenson plane. One of the advantages to being a good Swenson surgeon is that if you have to do a redo on a suave, it's sort of nice to find that plane, because you're finding the plane outside of their original, the previous original pull-through, which frees up fairly quickly. And then outside of that is the cuff. So from that perspective, you then want to find the actual Swenson plane, which is outside of that retained cuff, which has never been operated on because it's an areolar space. Okay. So Mark, let's just quickly, in bullet point format here, give us a summary on how you would manage each of these. So we talked about the transition zone pull-through. What about a patient that has an inadequately divided cuff or persistent cuff? So I would dissect that pull-through, outside of that pull-through, and actually within the cuff, so that the pull-through is neatly dissected. And then outside of that is all cuff. And you have to then make that plane between the cuff and essentially the Swenson plane, and then essentially remove that ring. And if there's good ganglion cells and good nerves, then that's all you need to do, and reconnect the pull-through with the colonel anastomosis. So just to clarify, you start with a dissection between the bowel and the cuff, get that separated out, and then you make a second plane outside of the cuff in the Swenson plane, and you actually remove that muscular tissue. Correct. And I actually put stitches in the cuff and then begin dissecting the cuff itself. I don't think you have to remove the entire circle, and you probably want to stay away from the anterior. That's what I was going to ask you. Okay. Where the urethra and the vagina could be. Yep. You basically just want to break the ring. So I'll start lateral, and more aggressive posterior, where there really isn't anything to hurt. And as long as you have broken that ring, you've solved the kid's problem. Okay. So then is a myectomy okay for that patient? So that's a very interesting question. I actually think that the myectomies that have been traditionally successful may very well have been myectomies that were done for suave cuff situations, but the surgeons didn't necessarily know that that's what they were cutting. People thought, I believe when they do a myectomy, people think that they're cutting the internal sphincter somehow. But most likely, they're cutting the cuff. And the problem with myectomies is if you set up 10 ORs and said to 10 surgeons, do a myectomy, and you videotape them all, they would all look very different. Because I think we all have a different concept of what we're actually cutting. But if you cut the cuff from the outside, you're doing exactly the same thing that I'm proposing. I just think it's a lot neater to do it this way. And often there's an additional indication, like transition zone bowel or something like that. And that's why I've chosen to do it that way. But if you want to do myectomies, and I personally would strongly argue against them because they can hurt more than you want to hurt. Namely, they can hurt the skeletal muscle and leave the patient incontinent. But that's the only way a myectomy might work is if it cuts the cuff. So when you do your cuff operation, and we just talked about that you don't need to remove the whole cuff, just the posterior aspect of it, then do you... I would say posterior and lateral. Posterior and lateral. Fair enough. And then do you need to dissect your bowel away on the anterior aspect? Or can you leave all of that intact and just do posterior lateral dissection? You could, although it's hard to do that. It's hard to get to see the cuff without a circumferential dissection. Fair enough. But theoretically, you could do that. I have never done that because it's just so nice to dissect the circumferential plane. You can see really, really well. Got it. Okay. And then along those lines, to help make your diagnosis, I know that you mentioned you can see the indentation on the contrast study that you can tell on physical exam. What is the role of Botox to help make a diagnosis or even treat? So this is a very interesting concept. And I can tell you my understanding of this has dramatically improved since I've started to collaborate with GI motility experts here at Nationwide. And I really didn't understand this, honestly, before. But if you correlate some of these problematic patients with their anal rectal manometry findings, you will note that a number of Hirschsprung's patients have tight sphincters, meaning the internal sphincter is very, very powerful and fails to relax. The one thing I really want to mention is that a lot of people assume that all Hirschsprung's problems are sphincter related. And I would actually think, I actually think that post-pull through sphincter problems are relatively rare compared to all these other anatomic things that we've talked about. So it's not usually the sphincter. But if every other anatomic possibility has been ruled out, and we've gone through that list, and if the pathology is okay, and the kid is still behaving as an obstructed child, then you must conclude that it is the sphincter. You can confirm that with anal rectal manometry. But of course, they have a problem opening that sphincter. By definition, that's part of Hirschsprung's disease. They ought to learn how to do that better over time. So this problem is relatively rare in the child that's over one year of age. But the child that's having enterocolitis episodes with no anatomic problem, that is a child that I would Botox. And what Botox does is essentially is a temporary myectomy. And I much prefer that strategy because then it wears off. And by the time the kid gets a little older and learns how to coordinate their stooling with their sphincter relaxation, they no longer need it. Whereas a myectomy is permanent and can lead to permanent harm and incontinence. I'd much rather do a series of Botoxes than any myectomy, because eventually the kids figure out how to poop properly. Huh. That's interesting. I never realized that because it seems to me it's just a very temporary fix. But no, they overcome it. In fact, we often will try to coordinate in the kid that's sort of learning how to do it. If you Botox them, and then at about four to eight weeks later, you start hitting them more aggressively with laxatives. They can't hold it in as well because of the Botox, but they have a little bit of tone back because the Botox is wearing off. And then they sort of learn how to have an appropriate bowel movement pattern. So, but wouldn't Botox also give you relief if it was a cuff problem? Yes. If you're aggressive in your Botox injection and it migrates up to where the cuff is, you will have improvement. But that's a patient that will not get better over time. Mm-hmm. They will be temporarily better and they will keep recurring their episodes. Okay. Because that cuff has got to go. But yes, you will improve things in the short term. Mm-hmm. But I want a long-term fix. Yeah. No, I mean just to help you make a diagnosis between a sphincter issue and a cuff problem, Botox might help improve both of those situations. Yeah. I will tell you that also interestingly, if you work with your gastroenterologist and do veinorectal manometry, we've actually gotten so neat about the study that they will actually tell me the length of high tone. Wow. So, the patient could, if the patient has one centimeter of high tone or failure to relax, that's sphincter. But three or four centimeters of tone is not sphincter. That's sphincter plus cuff. Okay. That's a great discussion there. And so, before we move on to the soiling patient, there was a couple of other anatomic things you mentioned. So, let's talk about the twisted bowel. Do you go in and resect and untwist or what do you do? So, the twisted pull through I would handle very similarly. I would dissect in the Swenson plane around the pull through or literally around the pull through. And then dissect that all the way up to the peritoneal reflection. Often, you need to go into the abdomen too, either laparoscopically or laparotomy. I usually end up making an incision and not doing this laparoscopically because it's very hard to figure out the twist and the blood supply and to make sure you're pulling through a new healthy segment. But laparoscopy is certainly appropriate in these redos. I just usually go in open because they're very, very stuck. And you have to manipulate the left colic and preserve the sigmoid arcade, which is tricky. And then basically redo the pull through no longer twisted. You have to free it up all the way into the pelvis so that you literally deliver it back up into the abdomen and then you pull it through again. And when you... Go ahead. If there's good ganglion cells and good nerves, then all you have to do is resuture it into that correct position without removing any. And when you go in to operate on these patients, you're usually pretty sure from the contrast study that they're twisted? Yes. Although a number of circumstances, we've had kids that have been super sick that we couldn't irrigate well. So I suspected there was a twist. We did an ileostomy. And then in the elective setting, when the kid was all better, we discovered that in fact, it was twisted. You just have to assume that that is a possibility. You have to be vigilant in thinking that it could be on the list of trouble. Okay. So the final anatomic diagnosis that may cause trouble is a Duhamel pouch that's too big, inert, or causes the inability of the ganglionated bowel to successfully empty. And most Duhamel do well, but I can tell you the ones that don't do well, the solution is to remove the Duhamel pouch, which many people are very reluctant to want to do. And they have good reason for it because it is a very difficult reoperation. It's probably the hardest thing you do in Hirschsprungs is to redo a Duhamel. For some reason, the stapled connection of the two lumens causes a lot of pelvic fibrosis. And I can tell you, we wrote a paper about redos for Duhamel. And I really wanted to call the paper, the Duhamel pouch, why I have learned to hate you. Because it's really an operation that I start to cry during sometimes because it's so stuck. But it's necessary because you have patients sometimes that simply cannot empty through their Duhamel pouch. So do you basically redo a Duhamel again? No. No, what I'll do is I'll start transanal. I'll dissect around both the pull-through part on the back and the original rectum on the front. And you have to take great care to separate that. Even though it's virginal there, for some reason, you get a lot of fibrosis from the vagina or the urinary tract. Dissect that up as high as you possibly can go through the transanal approach without overstretching and then go into the abdomen. And it's a very deep pelvic dissection, which requires good retractors. There's a great retractor called the St. Mark's retractor, which you may know of that is lighted at the end. And you can put that deep in the pelvis. This is obviously open. And you dissect pulling the bladder forward or the vagina and uterus forward. And finding that plane in the anterior rectal wall circumferentially, that is not easy. And eventually, you find your dissection plane that you started from below. And that's sort of a special moment because you realize that there is light at the end of the tunnel, literally. And then you pull up the entire thing, the ganglionated bowel plus the pouch. And then what I do is I just transect and throw away the pouch plus the part that was mated to it and do a redo pull through now in Swenson format. Got it. Okay. That was a great review of all the different common technical problems that you see that cause obstructive hairsprungs after a pull through. Can we talk about now a different type of patient? This is a four-year-old that had a previous pull through and never had enterocolitis, but comes to you because the patient is having daily soiling. So let's first start with how you evaluate that patient. So a very common patient in all of our pediatric surgical practices. And, you know, once again, this is the challenge of anatomic correction and successful function. The families don't really care if you do a good pull through. They want to know if that pull through will work and if the child will stool normally. But I like to say that all patients with Hirschsprung's disease should be able to empty spontaneously and should be clean. And the concept that many of these folks will get better over many, many years, and eventually when they're teenagers, they'll get better, I think is wrong. I think we got to get these patients emptying well, which was the first part of our discussion, and clean. Those are the two challenges. The clean part is very dependent on their inherent capacity for bowel control. And by definition, patients with Hirschsprung's disease are born with a normal anal canal and a normal set of sphincters. If anything, their sphincters are too good. No Hirschsprung's patient is born with a missing anal canal. No Hirschsprung's patient is born with a weak sphincter. However, many, many soiling Hirschsprung's patients have both of these. And unfortunately, the only possible conclusion is that those are iatrogenic. And the way that happens is that the surgeon started the transanal dissection too low and invaded the dentate line. And essentially, there's no dentate line left. And you see these images, these pictures of, I mean, these patients who have essentially the colon and the most of the skin that looks essentially like a analplasty and anorectal malformation. That's not Hirschsprung's disease. Hirschsprung's disease is not supposed to look like that. Right. And then the other problem is the patient has been overstretched. And that is a relatively more recent phenomenon. It was common with the aggressive transabdominal laparotomy deep pelvic dissection. Now it's happening again with a too aggressive of a transanal dissection, which is why laparoscopy is beautiful because it avoids a lot of the deep transanal work. But if they have been overstretched to, so the surgeon could see, you may see a patient who sits there with an open anus, even when they're awake. And that's a destroyed sphincter. Now you can objectively assess that with anorectal manometry. And you can actually see that the sphincters are weak. And that obviously came from the actual pull through itself. So when I evaluate a soiling Hirschsprung's patient, number one responsibility is to figure out what was the original surgery, be it Suave or Duhamel or Swenson. And then during our examination under anesthesia that I've described, we want to see if the sphincters are patulous by visual exam, by rectal digital exam, by anorectal manometry, if you have that ability to correlate with your GI colleagues doing manometry. And we want to assess the integrity of the dentate line, whether it is circumferentially intact. So these patients should not be relaxed by the anesthesiologist? Well, I like to watch them when they're awake. And as they're going off to sleep, is a great time to do a digital rectal exam. And if they're able to squeeze your finger, then they have good sphincter tone. Many of them that are soiling don't have that capacity. And to do it again, objectively, you can do an anorectal manometry and you get the information of whether the sphincter is good or not. Any role for imaging? As far as the quality of the sphincter? Well, just imaging in the workup of a patient who's soiling. Yes, I always do a contrast study. I would say any problematic Hirschsprung patient needs a contrast study and an examination under anesthesia. Okay, great. So the contrast study findings that you're looking for in the soiling patient is the pull-through narrow or dilated. Okay. I sort of use the contrast study as a poor man's colonic manometry. So if the patient has a narrow, non-dilated pull-through, then they may be soiling because they're hypermodal. And if they have a very dilated pull-through, they may be soiling because they're hypomodal. So then based on whether they have an intact anal canal and sphincters, I make the assessment of whether they have good potential for continence. So the scenarios are as follows. One, if a patient has a good anal canal and a good sphincter and is non-dilated, they have capacity for bowel control. And the reason why they're soiling is because their colons are moving too fast. You got to slow them down. If their anal canal, number two, if their anal canal and sphincters are normal and their contrast study shows that they are dilated, they also have the capacity for bowel control, but they're moving too slow, they need laxatives to speed them up. Okay. Number three, if the patient has a lost anal canal or a lost sphincter or both, and they have a non-dilated bowel, non-dilated colon, they are soiling because they're hypermodal and don't have sphincter or anal canal ability to be clean. That's a patient who needs an enema program, a very small enema probably will do it through the trick and treatment for hypermotility with constipating diet, loperamide, amodium, and a water-soluble fiber. And the enemas are to keep them socially content? Correct. Okay. And the fourth scenario is a patient who has a destroyed anal canal and sphincter or both and a dilated colon. And that patient just needs a larger volume enema and doesn't obviously need any treatment for hypermotility. And those are the patients, those last two categories, who are fecally incontinent on the grounds of anatomy. Now, we're used to evaluating such patients from a fecal and cons point of view in anorectal malformations. And we know that those patients sometimes are not continent because of anatomy, but it's often because they weren't born with good sphincters and they certainly weren't born with an anal canal. But Hirschsprung's disease desoiling is different because Hirschsprung's disease soiling, patients ought to have a good anal canal and a good sphincter. And if they don't, it had to have something to do with the surgery. Right. And so I want to just make sure I understood the four categories or a better way of saying that is I want to make sure I understand what are the four reasons why someone would be soiling after Hirschsprung's operation. Number one is that they have a normal anal canal and sphincter control, but a hypermodal colon that needs to be slowed down with Imodium. The second one is a patient that has a normal anal canal and sphincter mechanism, but they have a hypomodal colon and that would be dilated on the contrast study and they would need some sort of pro motility agents like a laxative and maybe enemas or no enemas for them. Well, if a patient has the capacity for bowel control with good sphincters and good anal canal, they just need the right medical regimen. I will sometimes give them an enema program as a bridge, meaning to get them socially continent, make them feel good about themselves, get them into normal underwear, but in short order in the next several months, try them on laxatives and they should succeed. Okay. So we have the hypermodal colon, we have the hypomodal colon, we have a lost anal canal and sphincter mechanism, which you treat with low volume enemas. That's assuming that they don't have a very dilated colon. Well, your first question in a soiling patient is, do they have the capacity for bowel control or not? I think that's the, I think frankly, any patient with fecal incontinence, you need to ask that question. If there's a patient who walks into your office and their complaint is soiling and they have had a myelomeningocele, they likely do not have the capacity to have bowel control, even though their colorectal anatomy is perfectly normal. Okay. Okay. So in Hirschsprung's disease, the capacity for bowel control is determined by whether or not their sphincters and anal canal are intact. If they are, they have every reason to expect them to have normal bowel control. If they are not, they may not have the ability to have bowel control. And those that have the ability for bowel control can be treated usually with medicines, whereas those that don't have the ability for bowel control will need some sort of enema. That's correct. And the low volume or high volume is based on the caliber of their colon? Correct. Okay. And if you want to formalize it, you can do a colonic manometry. But most of the knowledge you need to achieve is in the contrast study itself. So are any of these soiling patients treated with any sort of surgical management? Well, the only surgical management relevant for a patient who has no capacity for bowel control would be a malone or a cecostomy. Okay. So I think that what I'm hearing is that, and I thought the quote you said before was great, in any patient that has Hirschsprung's disease that had a pull through that is having a problem, quote unquote, they are best evaluated with a contrast enema and an evaluation under anesthesia. Correct. And with those two pieces of data, the radiology and the exam, there really is no Hirschsprung's patient that you should not be able to figure out and improve. This is great. Mark, I thought this was a fantastic summary of things that give a lot of us pediatric surgeons a lot of anxiety. And these can be very difficult patients to manage. And I think in the future, I'd like to do a program on the specifics of bowel management and the protocols for laxatives, enemas, so on and so forth. But for today, I think we've covered quite a bit. And I really appreciate you taking the time yet again to help us understand some of the difficult situations with Hirschsprung's disease. Great. I enjoyed it. I think if you approach this in a methodical way and that every patient with a problematic pull through is evaluated with a sort of methodical approach and you start checking off these boxes, you will find a lot of solvable pathology out there. Perfect. Mark, thanks again so much. Have a great day today and hopefully we'll be talking to you again soon. Thank you, Todd. All right. Bye-bye. all right. all right. all right.