Not all small bowel pneumatosis is ischaemia: a case-based systematic review of non-ischaemic causes

BACKGROUND: Pneumatosis intestinalis (PI) involving the small bowel is often interpreted as a radiological surrogate for ischaemia, prompting urgent surgical intervention. However, non-ischaemic causes-particularly in the postoperative setting-are under-recognised. This case-based systematic review aims to explore and synthesise reported non-ischaemic aetiologies of small bowel PI. METHODS: We present the case of a 74-year-old man who developed small bowel PI following ileostomy reversal, with computed tomography findings initially suggestive of bowel ischaemia. In the absence of clinical or biochemical evidence of sepsis, he was managed conservatively and made a full recovery. A systematic review was conducted using PRISMA methodology across PubMed, Embase and Medline databases. Inclusion criteria focused on reports of small bowel PI in the English language. Data were extracted on clinical context, diagnostic modality, treatment and outcomes. RESULTS: A total of 24 articles were included, comprising one retrospective cohort and 23 case reports, yielding 37 patients. The most frequent aetiology was small bowel obstruction (59.4%). Rarer causes included a rapidly progressive scleroderma-like disease, congenital lymphangioma and mechanical ventilation. Although 72.9% underwent surgical intervention, 27% were successfully managed conservatively. Only 10.8% had a suspected ischaemic component, and six patients died. Radiological overlap with ischaemic PI was common, yet several patients improved without surgery and only two (5.4%) had confirmed transmural small bowel necrosis. CONCLUSIONS: Not all small bowel pneumatosis indicates ischaemia. Conservative management can be effective in carefully selected patients, guided by clinical status and serial imaging. Early recognition of non-ischaemic PI is crucial to avoid unnecessary laparotomy.