A 28-year-old man with a history of total colonic Hirschsprung's disease treated with a Duhamel-Martin procedure in infancy, presented with signs and symptoms of acute colonic diverticulitis. Flexible sigmoidoscopy demonstrated a 20 cm jejunocolonic anastomosis, consistent with his previous operation in childhood, with a large diverticulum at the proximal end of the anastomosis containing fecal concretions. The patient returned one month later after a course of antibiotics for definitive resection of the diverticulum. Intra-operative colonoscopy localized three large diverticula and resection of the involved segment was performed. The case is presented as an adult complication of total colonic Hirschsprung's disease treated with childhood resection and reconstruction.