A 69-year-old man presents with abdominal pain and gastrointestinal (GI) bleeding.

Fig. 93.1 (A–C) CT colonoscopy with insufflated carbon dioxide in the colon. Axial CT images of the pelvis show a small isodense lesion protruding in the wall of the sigmoid colon, consistent with a sessile polyp (arrow).

Sigmoid colonic polyp

• Colonic adenocarcinoma
  
• Inverted diverticulum
  
• Carcinoid
  
• Metastases
  
• Lipoma
  
• Leiomyoma
  
• Foreign bodies