When the NICU team says they are "thinking NEC" about your baby, the next question they will be working through is: how bad is it? The framework neonatologists use to answer that question is called Bell's staging, after a 1978 paper by surgeon Dr. Martin Bell that has shaped how doctors classify necrotizing enterocolitis ever since. The staging was later modified by Walsh and Kliegman in 1986 into the version used in most modern NICUs.
Bell staging matters for parents to understand because the stage drives nearly every important decision — whether to stop feeds, when to involve surgery, whether to operate, and what the prognosis looks like. It also matters for any future legal review of how the case was managed.
What Bell Staging Is
Bell staging is a clinical and radiographic system that places a baby with suspected or confirmed NEC into one of three stages (with sub-stages within each). The stages reflect:
- What the baby looks like at the bedside — vital signs, abdominal exam, feeding tolerance, alertness.
- What the abdominal X-ray (KUB) shows.
- What the lab values show.
A baby's stage can change in either direction over hours. A Stage I baby can deteriorate to Stage III in a single day, or improve back toward baseline with the right management. Serial assessment — re-examining the baby, re-imaging, re-checking labs every few hours during an acute episode — is the standard of care.
The Three Stages
Suspected NEC
Nonspecific systemic signs — temperature instability, apnea, bradycardia, lethargy — with mild abdominal findings (residuals, mild distension, occult or grossly bloody stool). Abdominal X-ray normal or showing only mild ileus. NEC is on the working differential but not confirmed.
Definite NEC (medical)
Stage I findings plus radiographic evidence of NEC — pneumatosis intestinalis (gas in the bowel wall), portal venous gas, or fixed dilated loops of bowel. The baby is sick. NPO, gastric decompression, IV antibiotics, and intensive monitoring are standard. Surgery is on standby but not yet required.
Advanced NEC (surgical)
Stage II findings plus severe systemic signs (hypotension, severe acidosis, DIC, oliguria) and/or radiographic pneumoperitoneum — free air outside the bowel, which signals perforation. Pediatric surgical intervention is required, either by laparotomy or by peritoneal drain depending on size and condition of the baby.
What Each Stage Looks Like Clinically
Stage I: suspected NEC
The baby looks "off" but not yet critically ill. Signs may include increased apnea spells, more bradycardia events than usual, mildly elevated or low temperature, and a soft but distended abdomen. Feeds are not being tolerated — large pre-feed residuals, occasional bilious aspirates, occasional blood in the stool. The X-ray either looks normal or shows nonspecific ileus (gas pattern that could be NEC or could be something else). At Stage I, the team will typically stop feeds, start IV antibiotics after blood cultures, decompress the stomach with an orogastric tube, and follow closely.
Stage II: definite medical NEC
The diagnosis is now confirmed. The radiographic finding that anchors Stage II is pneumatosis intestinalis — small bubbles of gas tracking in the wall of the bowel itself, produced by gas-forming bacteria inside the damaged intestinal tissue. Portal venous gas, when present, indicates more advanced disease, with bowel-wall gas tracking back through the mesenteric veins to the liver. Stage II care is essentially the same as Stage I but more intensive — broader antibiotic coverage, more frequent labs and imaging, often invasive monitoring. Pediatric surgery is consulted at this stage even if not yet operating, because deterioration can be rapid.
Stage III: advanced surgical NEC
Stage III is the surgical stage. The radiographic finding that defines it is pneumoperitoneum — free air in the abdomen, indicating that some portion of the intestine has perforated. Clinically the baby is in shock or near-shock: pressure support, ventilator changes, blood products, vasopressors. Surgical options are laparotomy (open exploration with resection of necrotic bowel) or primary peritoneal drainage (a small drain placed at the bedside in the most fragile babies), with the choice depending on size and stability. Stage III is associated with the highest mortality and the highest rate of long-term complications — short bowel syndrome, ostomies, strictures, and neurodevelopmental impairment.
Why parents should ask about the stage every day. The stage tells the team what to do. It tells you, as a parent, what is happening medically. Asking "what stage is my baby today?" during rounds is a reasonable, useful question that gets you a meaningful answer.
Why Bell Staging Matters for the Case
If your family is later considering a legal case, Bell staging matters in several ways.
First, it provides the timeline of the disease in the baby's chart. Charts that document daily Bell stage assessments tell the story of when the disease was recognized, how fast it progressed, and what decisions were made at each stage. Charts that do not document a stage often have other timeline problems too — vital signs not consistently recorded, X-rays not read in real time, surgery consults not made when warranted.
Second, the stage at the time of key decisions matters. Was the baby Stage II for 36 hours before a surgical consult was placed? Was a baby with pneumoperitoneum left without surgical evaluation? Were feeds restarted too aggressively in a baby still showing Stage I signs?
Third, it relates to the medical-vs-surgical NEC distinction that is central to many NEC formula lawsuits. Our companion guide on surgical NEC vs. medical NEC walks through how that line affects both treatment and litigation.
What the Records Show
For an NEC case, the records that matter for the staging timeline are:
- Nursing flow sheets with vital signs, abdominal exam findings, gastric residual volumes, and stool observations every shift.
- Each KUB (abdominal X-ray), with both the radiologist's interpretation and the actual image — many later disputes turn on whether pneumatosis was visible before it was officially reported.
- Lab values over time — CBC with differential, platelet count, CRP, lactate, blood gases, electrolytes.
- Daily neonatology progress notes documenting the assessment and plan, including any explicit Bell staging.
- Pediatric surgery consults, including the time the consult was requested and the time it was completed.
- Operative reports if surgery was performed, including the pathology of the resected bowel.
- The feeding history — what was being fed (donor breast milk, mother's own milk, cow's-milk formula brand and product), how it was advanced, and when each feed-related decision was made.
What This Means for Parents
Bell staging is not just medical jargon — it is the language doctors use to describe what is happening inside your baby's body and what they plan to do about it. Asking about it during rounds is appropriate. Writing down the stage and the day in your own parent journal is useful. Our in-NICU action guide covers the broader set of questions to ask and what to preserve.
Free, confidential case review. No fees unless we recover compensation for you.
- Read about surgical NEC vs. medical NEC: Surgical NEC vs. medical NEC.
- Read about reading a NICU progress note: Reading a NICU progress note.
- Read about donor milk and prevention: Donor milk programs and NEC prevention.
- See if your family qualifies: Do I qualify for an NEC lawsuit?
Sources
- Bell MJ et al. — "Neonatal Necrotizing Enterocolitis: Therapeutic Decisions Based on Clinical Staging" (Annals of Surgery, 1978). The original staging paper. ncbi.nlm.nih.gov
- Walsh MC and Kliegman RM — "Necrotizing Enterocolitis: Treatment Based on Staging Criteria" (Pediatric Clinics of North America, 1986). The modified staging in current use. ncbi.nlm.nih.gov
- American Academy of Pediatrics — Committee on Fetus and Newborn guidance on NEC. aap.org
- Vermont Oxford Network — NEC quality improvement collaboratives and outcome benchmarks. public.vtoxford.org
- NIH National Library of Medicine / PMC — Peer-reviewed research on NEC pathophysiology, staging, and outcomes. ncbi.nlm.nih.gov/pmc
- American Pediatric Surgical Association — Pediatric surgical management of NEC. eapsa.org