Refractory diverticular colitis with progressive ulcerative colitis-like changes extending to the rectum.

A 68-year-old man visited our department because of diarrhea and bloody stools. Colonoscopy revealed diverticula scattered in the sigmoid colon with localized mucosal edema and reddening. The mucosa became somewhat rough 9 months later, and had an erosive, ulcerative colitis (UC)-like appearance after a further 6 months, with these changes extending to the rectum. These findings led to a diagnosis of diverticular colitis (DC) with UC-like changes. The condition was refractory to treatment including drug therapy and was thus surgically treated. No cases of DC have been reported in Japan, and a refractory case of DC with progressive UC-like changes extending to the rectum is rare even in Europe and the USA.