When a Baby Is Born Without an Anal Opening: Understanding the First Operation

A plain-language guide to four studies from 2025 and 2026 on how surgeons build a newborn's temporary stoma, how long feeding takes to recover, and where this surgery should be done

About one baby in every few thousand is born without a normal anal opening. Most need an operation within the first two days to create a stoma — an opening on the tummy that lets stool leave the body until the anus can be rebuilt — and four studies published in 2025 and 2026 examined how that first operation is best done, how long babies take to feed normally afterwards, and whether the surgery should be concentrated in a few specialist hospitals.

A problem that is usually found in the first minutes of life

An anorectal malformation means the lower end of the bowel and the anus did not form in the usual way before birth. In some babies the anal opening is present but sits slightly too far forward, or is very narrow. In others there is no opening at all, and the bowel instead ends in a small connecting channel — called a fistula — that opens into the urinary tract in boys or into the vaginal area in girls. In the most complex form, called a cloaca, the bowel, urinary tract and genital tract all share a single passage [1], [2].

Unlike many newborn conditions, this one is usually diagnosed simply by looking: a midwife or doctor notices there is no anal opening where one should be, within minutes of birth. Between half and two-thirds of babies with an anorectal malformation also have another difference somewhere in the body — most often the heart, kidneys, spine or windpipe — so a series of scans and tests usually follows quickly [2]. Birth-defect registries across many countries put the frequency at between one in 2,500 and one in 5,000 births, with survival differing considerably between countries [3].

What families faced before modern surgery

For most of the twentieth century, operations to rebuild the anus gave uncertain results. Surgeons could not see the muscles that control bowel movements clearly enough to place the new anal opening precisely in the middle of them, and many children grew up with poor bowel control. That changed in 1982, when two surgeons, Alberto Peña and Pieter de Vries, described an approach in which the surgeon works through an opening made exactly in the midline from behind, using an electrical stimulator to identify the muscle fibres [4]. The operation, known as a posterior sagittal anorectoplasty, gave far better results and is still the standard today.

That advance created the pathway families now experience. Because the repair takes several hours of delicate work and needs a clean, empty bowel, it is usually not done in the first days of life. Instead the team makes a temporary stoma, lets the baby grow and feed for some weeks, performs the repair, and closes the stoma in a third operation. Babies whose bowel has a usable fistula can sometimes skip the stoma altogether. For everyone else, that first operation is where the pathway begins — and where a surprising number of problems begin. A review published in 2006 described stomas that slipped outward, stomas placed too close to the rectum so that the later repair became harder, stool leaking into the unused part of the bowel, and urine infections in boys whose bowel connected to the urinary tract; the authors argued nearly all of these could be prevented by how the stoma was built [5].

What the first operation actually involves

The surgeon makes a small cut in the lower left side of the abdomen and brings a loop of large bowel up to the skin. There are two broad ways of doing this. In a loop stoma, a single loop is opened, so both directions of the bowel share one opening. In a divided, or double-barrel, stoma, the bowel is cut across and the two ends are brought out separately: one delivers stool into a bag, and the other — called a mucous fistula — leads down toward the rectum and stays quiet.

The divided version has the advantage that stool cannot flow across into the lower bowel, which matters greatly for a boy whose bowel connects to his bladder or urethra. Its traditional disadvantage is that it needs two separate openings with a bridge of skin between them, making the bag harder to fit and leaving a larger scar. Surgeons have argued about this trade-off for decades without settling it.

Does keyhole surgery make the first operation safer?

A team at Karolinska University Hospital in Stockholm looked back at 44 newborns who had a stoma created between 2012 and 2022 — 14 with the help of a laparoscope, or keyhole camera, and 30 through a small open incision [6]. The results were closely similar. Babies in both groups had their operation at a median age of two days, started milk on the day of surgery, and went home after a median of about eight days. Complications serious enough to need treatment occurred in 2 of the 14 keyhole cases (14%) and 7 of the 30 open cases (23%) — a difference small enough to have arisen by chance in a study this size.

Five of the six stomas that slipped outward, a problem called prolapse, followed the open operation. That is a hint rather than a finding, because with so few babies the study cannot separate a real pattern from coincidence. What families can take from it is reassurance: whichever approach the surgical team uses, the early recovery looks much the same.

A newer way of building the stoma, designed with daily care in mind

At Oslo University Hospital, Norway's national referral centre for this condition, surgeons have for twenty years used a version of the divided stoma that brings both ends through a single opening in the skin — keeping the protection against stool crossing over, while needing only one bag and leaving a smaller scar. A review of 61 babies operated between 2012 and 2024 found complications in 12 (20%), most of them minor [7]. Two (3%) needed a further operation, and six (10%) developed a urinary infection, almost all in children whose anatomy already carried that risk. No baby's stoma prolapsed, and there was no sign of stool crossing into the lower bowel.

The most useful part of this study for families is something the authors deliberately counted separately. Five babies (8%) needed dressings changed more than twice a day, and 20 (33%) had smaller problems — leaking around the bag, sore skin — solved with sealing paste, different dressings, or a phone call to a stoma nurse. Fifty-nine per cent had no problems at all. These are not "complications" in the medical sense, but they are exactly what makes the weeks at home hard or manageable. Research asking parents directly describes the same picture: caring for a newborn's stoma brings real uncertainty and emotional strain, and easy access to a specialist nurse makes a substantial difference [8]. The smaller scar matters too, since children with this condition often have several operations and have told researchers that abdominal scarring affects how they feel about their bodies later on [9].

How long before your baby feeds normally again?

One question parents ask almost immediately is when their baby will feed properly again. A study from Rotterdam followed 34 newborns through this period [10]. Milk was usually restarted about two days after the operation, but reaching full feeds took a median of six days, and about a quarter of babies needed more than a week — mostly those with an additional heart, oesophageal or growth problem.

In the meantime, babies need nutrition through a drip. Half of that study's babies had a longer-lasting central line placed for this, and a few needed a second anaesthetic for it. The authors' practical suggestion — a reasonable thing to ask your team about — is that for babies likely to need this support, the line can be placed during the stoma operation itself.

Should this surgery happen in only a few hospitals?

Because the condition is rare, no individual surgeon sees many cases, and several countries have decided to concentrate care. Sweden reduced its centres from four to two in 2018. Researchers compared every baby in the country who had the anal repair in the five years before with every baby in the five years after — 349 children — and found no meaningful difference in readmissions, unplanned further operations, serious complications or length of stay [11].

This sounds like an argument against concentrating care, but it is more complicated. Swedish hospitals were already doing about nine of these repairs each per year before the change, and about eighteen afterwards — both above the minimum of ten a year European specialists recommend [12]. In Germany the same operation has been spread across more than a hundred hospitals doing roughly three a year each. Moving from nine to eighteen is a different question from moving from three.

A German expert panel tackled the problem differently [13]. Since a trial of "busy hospital versus quiet hospital" could never be run for a condition this rare, thirteen specialists worked systematically through whether evidence from adult bowel surgery — where the benefit of experienced, high-volume centres is well established — can reasonably be applied here. They concluded that it can, while being careful about which outcomes it applies to, and did not propose a specific number of operations per year.

What all of this means for your family

If your baby needs a stoma, none of these studies suggests one technique is clearly better than another, and your surgical team's usual approach is a reasonable one. It is fair to ask how the stoma will be built and what the plan is for feeding in the first week. Expect reaching full milk feeds to take roughly a week, and longer if your baby has other health problems. Expect some trouble with the bag or the surrounding skin — it affects around four in ten families and is almost always solvable — and ask to be put in direct contact with a stoma nurse before you go home. And if your baby's operation is to happen at a distant specialist centre rather than your local hospital, the evidence now supports that choice, even though the benefit is easier to argue than to measure.

What researchers are working on next

Three gaps stand out. None of these studies followed children long enough to say how stoma technique affects bowel control at school age, which is what families care about most. No study has yet compared stoma designs head-to-head in a planned way, so the loop-versus-divided argument continues. And the day-to-day burden of stoma care on parents, which the Oslo team measured thoughtfully, is still missing from almost every other study. Related questions about timing and feeding after newborn bowel surgery are explored in the In[Neo]Sight articles on when to operate in Hirschsprung disease and on getting babies off intravenous nutrition after bowel surgery.

References

  1. Levitt MA, Peña A. Anorectal malformations. Orphanet J Rare Dis. 2007;2(1):33. doi:10.1186/1750-1172-2-33 ↩
  2. de Blaauw I, Stenström P, Yamataka A, et al. Anorectal malformations. Nat Rev Dis Primers. 2024;10(1):88. doi:10.1038/s41572-024-00574-2 ↩
  3. Kancherla V, Sundar M, Tandaki L, et al. Prevalence and mortality among children with anorectal malformation: a multi-country analysis. Birth Defects Res. 2023;115(3):390–404. doi:10.1002/bdr2.2129 ↩
  4. Peña A, Devries PA. Posterior sagittal anorectoplasty: important technical considerations and new applications. J Pediatr Surg. 1982;17(6):796–811. doi:10.1016/S0022-3468(82)80448-X ↩
  5. Peña A, Migotto-Krieger M, Levitt MA. Colostomy in anorectal malformations: a procedure with serious but preventable complications. J Pediatr Surg. 2006;41(4):748–756. doi:10.1016/j.jpedsurg.2005.12.021 ↩
  6. Axelsson G, Gunnarsdóttir A, Wester T, Löf Granström A. Laparoscopically assisted versus open colostomy for anorectal malformations: a comparison of postoperative outcomes. Pediatr Surg Int. 2025;41(1):232. doi:10.1007/s00383-025-06108-5 ↩
  7. Olsbø S, Austrheim AI, Hoel AT, Bjørnland K. Neonatal single-site divided colostomy in anorectal malformation. Pediatr Surg Int. 2026;42(1):276. doi:10.1007/s00383-026-06507-2 ↩
  8. Ni ZH, Ding S, Wu JH, Wang F. Family caregivers' experiences of caring for neonates undergoing enterostomy in China: a qualitative study. Nurs Open. 2023;10(2):817–827. doi:10.1002/nop2.1350 ↩
  9. Tofft L, Klasson S, Salö M, Hambraeus M, Arnbjörnsson E, Stenström P. Patient-reported physical and psychosocial significance of abdominal scarring in anorectal malformations. J Pediatr Surg. 2022;57(10):348–353. doi:10.1016/j.jpedsurg.2021.11.022 ↩
  10. Huijgen D, Schokker-van Linschoten IK, Versteegh HP, Sloots CEJ. From colostomy creation to full enteral feeding in neonates with an anorectal malformation: evaluating the role of central venous access. Front Surg. 2025;12:1524404. doi:10.3389/fsurg.2025.1524404 ↩
  11. af Petersens M, Stenström P, Borg H, et al. Short-term outcomes of centralization on surgical care for patients with anorectal malformations: retrospective cohort study. BJS Open. 2026;10(1):zraf155. doi:10.1093/bjsopen/zraf155 ↩
  12. Aubert O, Irvine W, Aminoff D, et al. ERN eUROGEN guidelines on the management of anorectal malformations, part IV: organization of care and communication between providers. Eur J Pediatr Surg. 2024;35(2):128–134. doi:10.1055/s-0044-1791248 ↩
  13. Aubert O, Kuru TH, Samans M, et al. Indirect evidence for the volume-outcome relationship for corrective surgery for anorectal malformations using the IQWIG V24-07 rapid report methodology. Pediatr Surg Int. 2026;42(1):322. doi:10.1007/s00383-026-06519-y ↩