Search

Optical colonoscopy represents the diagnostic and therapeutic gold standard for most colonic pathologies, including screening for colorectal cancer and removal of polyps. Although in the last years alternative techniques have been developed in order to improve patient tolerance to colonoscopy, it remains associated with potential pain and discomfort and still has a risk for morbidity and mortality. Following diagnostic or therapeutic colonoscopy, imaging may be requested to investigate suspected iatrogenic complications, particularly perforation and haemorrhage. After endoscopy, radiographic and CT imaging generally show gaseous distension, absence of faeces and possible air–fluid levels of the large bowel. Metallic clips may be observed after endoscopically control of post-polypectomy bleeding. The post-polypectomy electrocoagulation syndrome (PPES) is characterised by focal colonic wall thickening and adjacent peritoneal inflammation in absence of perforation, demonstrated by CT imaging after polypectomy with electrocautery. Clinically, PPES closely mimics signs and symptoms of colonic perforation, but is a self-limiting condition which is amenable to a conservative therapy. Radiologists’ awareness of this entity and CT differentiation from perforation are crucial to obviate unnecessary invasive treatments. A typical case of PPES is presented.

Optical colonoscopy carries a low but real risk for morbidity and mortality, which increases as endoscopy assumes a more therapeutic role. Adverse event rate is about 0.3 % and almost 85 % of serious complications occur in patients undergoing polypectomy. Perforation and haemorrhage, the commonest specific complications, may be unrecognised during the procedure. Furthermore, clinical symptoms and laboratory signs often develop late; therefore, prompt adequate imaging is mandatory in case of clinical suspicion. Plain radiographs have limited sensitivity in detection of pneumoperitoneum and extraperitoneal gas. Multidetector computed tomography (CT) represents the best technique to assess free air or fluid, colonic injuries and bleeding.