Giant sigmoid diverticulum: A case report.

Sigmoid colon diverticulosis is commonly seen in both the surgical outpatient and emergency departments. Rarely, these sigmoid diverticulum, which usually range from 2-3mm to 2cm in size, can enlarge to more than 10 times. This is due to a ball-valve type mechanism that traps colonic gas inside the sigmoid diverticulum causing it to gradually enlarge. Patients with a giant sigmoid diverticulum (GSD) must be investigated thoroughly as two per cent of patients will present with a colonic carcinoma either within or distal to the GSD. Clinical symptoms of a GSD can range from chronic abdominal pain, altered bowel habits, abdominal distention, weight loss, bleeding, perforation, fistula formation, or bowel obstruction. CT and plain abdominal x-ray is the investigation of choice for its diagnosis. Barium enema is useful to determine the presence of a carcinoma within the GSD. Sigmoidoscopy is useful to rule out a distal colonic carcinoma. This is the first published case where nocturnal diarrhoea is the primary differentiating symptom in the patient. The treatment of choice for a GSD is complete resection of the diverticulum and/or the adjacent sigmoid colon. This can be performed with a primary anastomosis or a double-stage procedure.