Hematochezia and colitis in a new diagnosis of anorexia nervosa in an 11-year-old boy: a case report

Background To our knowledge, this is one of the first case reports describing hematochezia and acute colitis as a consequence of refeeding in the setting of severe malnutrition. The differential diagnosis was broad and included ischemic (for example, possible reperfusion-like injury following refeeding), infectious, and autoimmune/inflammatory (for example, inflammatory bowel disease) etiologies. This presentation is rare, particularly in early adolescents and boys. Case presentation This case report describes an 11-year-old boy who intentionally restricted his food intake for six months, resulting in a 17.1-kg weight loss (from 50.9 kg to 33.8 kg), and who presented after 72 h without oral intake. Shortly after initiating enteral nutrition via nasogastric tube, the patient developed significant hematochezia associated with a fever, tachycardia, and a marked elevation in C-reactive protein and fecal calprotectin. A computed tomography of the abdomen was concerning for diffuse ischemic colitis of unclear etiology, leading to a diagnostic laparoscopy, which demonstrated an edematous, acutely inflamed colon with no areas of ischemia. Conclusions The present case highlights an unusual gastrointestinal complication of severe malnutrition and the refeeding process.