Treating a Serious Bowel Illness in Premature Babies — and How Much Doctors Really Know

What research on antibiotics and on restarting milk reveals about the evidence behind necrotizing enterocolitis care

A frightening illness with a familiar treatment

Necrotizing enterocolitis — usually shortened to NEC — is one of the most serious illnesses that can affect a premature baby. It is an inflammation and injury of the bowel that can come on quickly and make a baby very unwell ^[1]. When NEC is diagnosed, the response is much the same in hospitals everywhere: the baby is stopped from taking milk, a small tube empties the stomach so the bowel can rest, antibiotics are started to fight infection, and nutrition is given directly into a vein while the gut recovers. This staged approach, organised around how severe the illness is, goes back to a framework first set out in the late 1970s ^[2].

What may surprise families is how much of this routine is based on experience and tradition rather than on the strongest kind of medical proof. The strongest proof in medicine comes from “randomized trials,” in which babies are randomly assigned to one approach or another so the two can be fairly compared; for many of the everyday choices in NEC care, those trials have simply never been done. This article looks honestly at that gap, walking through the two big decisions doctors make for a baby who already has NEC — which antibiotics to give and for how long, and when to restart milk — and what the research actually shows about each.

Antibiotics: essential, but chosen largely by habit

Antibiotics are considered a cornerstone of NEC treatment, and almost every baby with NEC receives them. Yet there is remarkably little hard evidence about which antibiotics are best or how long to give them. A 2022 review that gathered all the available studies found only five worth including, covering 375 babies in total — and just two of those were the rigorous kind of study (a randomized trial) that doctors most trust ^[3]. The review found that no particular combination of antibiotics worked better than another, and that the length of treatment did not clearly change outcomes. The most commonly used combination is used mainly because it is familiar, not because it has been proven superior ^[3].

A 2023 review by experts raised an even more interesting point about one long-standing habit: adding a drug to cover “anaerobic” bacteria (germs that live without oxygen) ^[4]. These experts pointed out that such bacteria are actually uncommon in the immature gut of a premature baby, and that adding drugs to target them may not help — and might even slightly raise the risk of the bowel narrowing as it heals ^[4]. In other words, a routine practice may not be doing what everyone assumed, and the truth is that no one yet knows for sure.

Because the evidence is so thin, many hospitals have turned to “antibiotic stewardship” — carefully standardising and, where safe, shortening antibiotic courses to give no more than a baby truly needs. Programmes that did this did not see worse outcomes, which is reassuring, and they also reduced the number of days babies spent on antibiotics and with intravenous lines ^[5]. Shortening the antibiotic course can also matter for another reason, as the next section explains.

Resting the bowel: why longer is not automatically safer

While a baby is kept off milk — doctors call this “nil by mouth” — all nutrition comes through a thin tube into a vein, which usually needs a special long line placed into a larger blood vessel. These lines are life-saving, but the longer they stay in place, the greater the chance of a bloodstream infection, and feeding into a vein for a long time can also place a strain on the liver. The bowel itself actually needs milk to heal — even tiny “trophic” amounts, given not for nutrition but to keep the gut active and healthy — so an overly long wait can cause its own problems ^[6]. The traditional wait of one to two weeks was based on caution rather than on studies comparing different lengths. And because many hospitals restart milk only when the antibiotic course finishes, an unnecessarily long course of antibiotics can keep a baby off milk longer than needed — one more reason the two decisions are connected.

Restarting milk: more studied, but still no definitive trial

The decision about when to restart milk has been studied a little more — though, strikingly, still never in a randomized trial. The most useful research is a 2020 analysis by Dr. Ekta Patel and colleagues, who combined three earlier studies comparing babies fed again earlier (around four days after diagnosis) with babies fed again later (around ten days) ^[7]. The combined group included 79 babies fed earlier and 119 fed later. Babies fed earlier had a lower chance of a combined problem the researchers tracked — NEC coming back, or a “stricture,” a scar-like narrowing of the bowel that sometimes needs an operation — and, importantly, earlier feeding caused no extra harm ^[7].

The researchers were honest about the limits: the studies were small, none was a randomized trial, and when the two problems were looked at separately the results were not strong enough to be sure about each one alone. The confident conclusion was about safety — feeding earlier did not appear to cause harm ^[7]. One of those earlier studies, for instance, restarted milk only after signs of gas in the bowel’s blood vessels had cleared on an ultrasound scan, letting the baby’s own recovery rather than the calendar signal readiness ^[8].

In 2024, a panel of European childhood-nutrition experts reviewed everything known about feeding babies after NEC and reached a frank conclusion: there still isn’t enough high-quality research to say definitively what is best, and hospitals vary widely ^[9]. They gave two clear pieces of practical advice all the same — a mother’s own milk is the best choice when feeds restart, and every unit should have a clear written feeding plan agreed by doctors, surgeons, nurses, and dietitians together ^[9]. Simply having and following an agreed plan has been shown to shorten the time babies spend without milk and on intravenous nutrition, without causing more complications ^[5].

A new study on the most serious cases

The most severe NEC involves a hole forming in the bowel — a perforation — which needs an operation. A 2025 study from a children’s hospital in Chongqing, China, by Dr. Wen Luo and colleagues, focused on this group: 90 full-term babies who had surgery for NEC with a perforation ^[10]. Babies fed earlier (around five days after surgery rather than nine or more) had far less bowel narrowing (about 44% versus 78%), needed fewer repeat operations, and went home sooner — about 14 days instead of 20 — while also coming off intravenous nutrition sooner ^[10]. Increasing the milk more quickly got babies home and off intravenous nutrition faster, but those babies gained weight more slowly during that period — a genuine trade-off rather than a clear win ^[10]. Reassuringly, this group had no bloodstream infections, no NEC recurrences, and no deaths. It was a single hospital studying full-term babies, so the findings don’t automatically apply to every premature baby, but it is the most detailed and useful recent look at feeding after surgery for NEC.

What this means for your family

The overall message is reassuring even though the evidence is incomplete. The modern approach — careful antibiotic use and restarting a mother’s milk reasonably soon, once the team sees clear signs the bowel has settled — is supported by the best evidence available, and waiting longer than necessary is not a safer choice. The fact that much of NEC care rests on experience rather than proof is exactly why teams rely on careful protocols and watch each baby closely, adjusting as they go. With babies who needed surgery, some stops and starts in feeding are a normal part of recovery, not a setback. It can help to ask your baby’s team what signs they are watching for and what their unit’s plan looks like.

There is also something families can do: because a mother’s own milk is the preferred feed when milk restarts, expressing and storing milk during the waiting period is a real and valuable contribution. If a mother’s own milk is not available, there are well-described alternatives, including donor human milk, that the team can discuss ^[6].

What researchers are working on next

The biggest gap is the lack of large, rigorous trials — and researchers are calling for exactly that, both for antibiotics (including whether that routine anaerobic-coverage drug helps or harms) and for the timing of refeeding ^[4]. Standardised feeding plans are already spreading because they help ^[5]. Looking further ahead, scientists are exploring entirely new treatments to help the injured bowel heal, including therapies based on stem cells and the tiny “messenger” particles they release; these are promising in laboratory studies but not yet ready for babies ^[11]. For now, the most powerful tools remain the simplest: a mother’s milk, a watchful team, and a clear plan — and a recognition that careful, consistent care is the right response to a field still waiting for definitive answers.

References

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2. Bell MJ, Ternberg JL, Feigin RD, et al. Neonatal necrotizing enterocolitis: therapeutic decisions based upon clinical staging. Annals of Surgery. 1978;187(1):1–7. doi:10.1097/00000658-197801000-00001 ↩
3. Gill EM, Jung K, Qvist N, Ellebæk MB. Antibiotics in the medical and surgical treatment of necrotizing enterocolitis: a systematic review. BMC Pediatrics. 2022;22(1):66. doi:10.1186/s12887-022-03120-9 ↩
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6. Embleton ND, Zalewski SP. How to feed a baby recovering from necrotising enterocolitis when maternal milk is not available. Archives of Disease in Childhood — Fetal and Neonatal Edition. 2017;102(6):F543–F546. doi:10.1136/archdischild-2016-311964 ↩
7. Patel EU, Wilson DA, Brennan EA, Lesher AP, Ryan RM. Earlier re-initiation of enteral feeding after necrotizing enterocolitis decreases recurrence or stricture: a systematic review and meta-analysis. Journal of Perinatology. 2020;40(11):1679–1687. doi:10.1038/s41372-020-0722-1 ↩
8. Bohnhorst B, Müller S, Dördelmann M, et al. Early feeding after necrotizing enterocolitis in preterm infants. Journal of Pediatrics. 2003;143(4):484–487. doi:10.1067/S0022-3476(03)00443-800443-8) ↩
9. Mo I, Lapillonne A, van den Akker CHP, et al. Nutritional management after necrotizing enterocolitis and focal intestinal perforation in preterm infants. Pediatric Research. 2024. doi:10.1038/s41390-024-03386-y ↩
10. Luo W, Cao H, Hu Y, et al. Optimizing nutritional strategies in term NEC and perforation infants after intestinal operation: a retrospective study. Scientific Reports. 2025;15(1):5577. doi:10.1038/s41598-025-90366-9 ↩
11. Villamor-Martinez E, et al. Stem cell therapy as a promising strategy in necrotizing enterocolitis. Molecular Medicine. 2022;28(1):107. doi:10.1186/s10020-022-00536-y ↩