Turnbull Stoma

Why This Technique Exists

In pediatric colorectal surgery — particularly for anorectal malformations and Hirschsprung disease — temporary fecal diversion is often necessary before definitive pull-through reconstruction. The traditional approach was a double-barrel colostomy, in which the bowel is divided and both ends are brought to the skin as separate stomas. The Turnbull loop stoma emerged as an alternative that preserves mesenteric blood supply to the distal segment while still providing complete diversion. This matters because the distal colon and rectum must remain viable for later reconstruction 0:51.

The Core Problem

When creating a double-barrel stoma, the surgeon must divide the mesentery between the proximal and distal limbs. During this division, key collateral vessels to the distal segment can be easily ligated 1:33. The discussant demonstrates this risk with an image from a colostomy closure, showing how tenuous the mesenteric supply to the distal limb can become. If those collaterals are compromised, the distal colon may not heal well or may develop stricture — a problem that only becomes apparent months later when you attempt the pull-through.

The Turnbull stoma solves this by creating a loop configuration in which no mesentery is divided 1:50. The bowel remains in continuity, the blood supply is undisturbed, and the distal segment is preserved for later mobilization.

How the Technique Works

The Turnbull stoma is a loop that functions like an end stoma 1:58. To the ostomy nurse or the family, it looks like a conventional end colostomy — a single, everted, functional opening. But anatomically it is a loop, with a tiny, flat mucous fistula representing the distal limb 1:08. The asymmetry is deliberate: the proximal limb is everted and matured as the functional stoma, while the distal limb is left nearly flush with the skin.

The discussant now performs this laparoscopically, identifying the appropriate bowel segment before exteriorizing it 0:20. The proximal sigmoid is chosen deliberately, preserving the distal sigmoid and rectum for the eventual pull-through 0:51. The stoma site is marked on the flat portion of the left lower quadrant, bounded by the ribs, anterior superior iliac crest, and pubic bone 0:36 — standard landmarks, but worth confirming in an infant whose abdominal wall proportions differ from an adult's. The site should be some distance from the primary incision 2:33.

Once the loop is exteriorized, the bowel is opened on the anti-mesenteric side 3:21. The key technical feature is the asymmetric maturation: the separation between proximal and distal limbs is described as "90 to 10" 3:30, meaning the proximal opening is large and the distal opening minimal. The seromuscular layer is tacked to the fascia, and the two corners are tacked to the dermis 3:43. This fixation is not decorative — prolapse is the main complication of loop stomas 3:50, and secure fascial fixation is the primary defense against it. The proximal limb is then everted using a retractor, turning it inside out to create the appearance of an end stoma 4:22.

Where Practice Is Contested

The discussant notes that this represents a recent change in technique — they previously performed double-barrel stomas and have shifted to the Turnbull approach 0:29. This is not a universal standard; many pediatric surgeons still perform double-barrel colostomies, particularly in settings where the distal segment is not intended for later use or where the anatomy makes loop exteriorization difficult. The Turnbull technique requires adequate sigmoid length and mobility — if the sigmoid is short or the mesentery is thick and unyielding, a loop may not reach the abdominal wall without tension.

The discussant also mentions performing this as an ileostomy in a case of Hirschsprung disease, noting it was "ideal to show you the Turnbull technique." This suggests the principle applies across bowel segments, though the prolapse risk may differ between ileum and colon.

When to Involve This Team

If you are managing an infant with an anorectal malformation or Hirschsprung disease, the decision to divert is typically made by the pediatric surgeon at the time of initial evaluation or during a complicated pull-through. The Turnbull stoma is not a rescue procedure — it is a planned diversion strategy chosen when the distal bowel must be preserved for later reconstruction. If you are a neonatologist or general pediatrician following a baby with a new colostomy, understanding whether it is a loop or a divided stoma helps you anticipate the closure plan. If the stoma prolapses — the complication the discussant emphasizes 3:50 — that is a reason to involve the surgical team, though it is not always an emergency. The timing of stoma closure and pull-through depends on the child's growth, the underlying diagnosis, and the surgeon's assessment of distal bowel viability — typically months after the initial diversion.

Why This Technique Exists

Pediatric colorectal surgery frequently requires temporary fecal diversion — most commonly in newborns with anorectal malformations or Hirschsprung's disease awaiting definitive pull-through 0:20. The traditional approach was a double-barrel colostomy created through a left lower quadrant incision 0:29. The Turnbull loop stoma emerged as a solution to a specific technical problem: preserving mesenteric blood supply to the distal bowel segment while achieving complete fecal diversion 1:50.

The Core Problem

When creating a double-barrel stoma, the surgeon divides the bowel completely and brings both ends to the skin 0:29. This requires taking mesentery between the two limbs. During this division, key collateral vessels to the distal segment can be easily ligated 1:33. The distal sigmoid and rectum must remain viable for months until the child is ready for pull-through reconstruction 0:51. Compromising that blood supply at the initial diversion creates risk at the definitive operation 1:33.

The Turnbull stoma solves this by creating a loop configuration that functions like an end stoma but takes no mesentery 1:50. The proximal limb is everted to handle all fecal output while the distal limb remains flat and minimally productive — appearing to the ostomy nurse as an end colostomy with a small mucous fistula 1:08.

How the Technique Works

Segment Selection

The proximal sigmoid should be chosen for stoma creation to preserve the distal sigmoid and rectum for ultimate pull-through 0:51. The sigmoid colon has anatomical variation; selecting too distal a segment leaves insufficient length for later reconstruction 0:51.

Current practice favors laparoscopy to identify the appropriate bowel segment before exteriorization, rather than the traditional open left lower quadrant approach 0:20. This allows direct visualization of the sigmoid anatomy and precise segment selection 0:20.

Site Preparation

The stoma should be matured on the flat portion of the left lower quadrant between the ribs, anterior superior iliac crest, and pubic bone 0:36. The site should be at some distance from the primary incision 2:33. A circular skin excision is made and subcutaneous fat removed 0:36. The fascia is incised and the selected bowel loop delivered through the opening 0:36.

Creating Asymmetric Function

The technical key is creating a loop with the proximal side brooked and the distal side flat 2:06. The bowel is opened on the anti-mesenteric side 3:21. The separation between proximal and distal limbs is 90 to 10 3:30 — meaning the proximal opening receives most of the circumference while the distal limb remains nearly closed 3:30.

The seromuscular layer is tacked to the fascia and the two corners are tacked to the dermis 3:43. This fixation is critical because the main complication related to a loop stoma is prolapse 3:50. Using a retractor, the proximal limb is turned inside out to create the appearance of an end stoma 4:22. This eversion ensures all fecal stream exits through the proximal opening while the distal limb functions only as a mucous fistula 1:08.

Where Practice Has Shifted

One of the discussants notes that the technique has recently changed from double barrel to loop stoma 0:29. This represents a conceptual shift: accepting that complete bowel division is unnecessary if the functional result — total fecal diversion — can be achieved while preserving mesenteric integrity 1:50. The Turnbull configuration delivers that result 1:50.

The move toward laparoscopic segment identification 0:20 rather than open exploration reflects broader trends in pediatric surgery, but the principle remains anatomic precision in selecting the proximal sigmoid 0:51.

When to Use This Approach

The discussion centers on temporary diversion in pediatric colorectal conditions — specifically anorectal malformations and Hirschsprung's disease 0:20. The technique is particularly valuable when the distal bowel will be needed for later reconstruction 0:51. Any scenario requiring temporary diversion with planned reversal benefits from mesenteric preservation 1:33 1:50.

One of the discussants demonstrates the technique using an ileostomy for Hirschsprung's disease, noting it was ideal to show the Turnbull approach despite the different bowel segment 1:58. This suggests the principle applies beyond sigmoid colostomy to any loop diversion where asymmetric function is desired 1:58.

For the referring physician, the key question is not whether to use Turnbull versus double-barrel — that is the surgeon's technical choice — but rather understanding that modern temporary diversion prioritizes preserving blood supply to the defunctionalized segment 1:33 1:50. If you are consulting pediatric surgery for a newborn with anorectal malformation or Hirschsprung's disease, expect the diverting stoma to be created with this principle in mind 0:20 1:50.