Biphasic small bowel perforation after blunt abdominal trauma: a case report of delayed ischaemic progression and re-perforation

Blunt bowel and mesenteric injuries (BBMI) are diagnostically challenging and may evolve despite apparent radiological resolution. This case describes biphasic small bowel perforation following non-operative management (NOM) after blunt abdominal trauma, highlighting limitations of conservative strategies and the need for prolonged vigilance. A 57-year-old woman sustained a Grade 4 small bowel perforation after a motor vehicle collision. She presented 7 days post-accident with abdominal pain but was haemodynamically stable and elected NOM. Interval computed tomography at 23 days demonstrated apparent resolution. At 21 weeks, she re-presented with crescendo abdominal pain, nausea, and vomiting. Imaging confirmed recurrent perforation at the original site. Laparotomy revealed a 3 cm full-thickness perforation adjacent to a chronic fibrotic stricture and mesenteric defect. Ileocolic resection was performed. Radiological resolution does not equate to definitive healing in high-grade BBMI. Trauma-induced chronic ischaemia may drive delayed stricture formation and late perforation, warranting structured long-term follow-up, and patient education.