Post-colonoscopy Pseudotumour: A Rare Cause of Post-colonoscopy Acute Abdomen

A 41-year-old male, with a change in bowel habits and a positive faecal immunochemical test, underwent a routine colonoscopy without complications. The following day, he presented with an acute abdomen, with raised inflammatory markers and sepsis. Computed tomography of the abdomen and pelvis (CTAP) revealed stenosing lesions in the ascending colon and small bowel, with upstream dilatation. In view of the normal colonoscopy, we postulated that this could be due to bleeding into the colonic wall from the biopsies. A follow-up CTAP showed complete resolution of the masses with no further symptoms. Literature suggests that the likely cause was haemorrhage, leading to laminar mural thickening. Conservative management is usually sufficient for such cases. Correlating the clinical presentation, colonoscopy, pathology, and radiology results is important in the management of this rare complication. This case highlights a rare cause of acute abdomen. Awareness of such complications and correlating the various imaging modalities is crucial for patient management and avoiding unnecessary surgery.