Adult segmental Hirschsprung disease.

Hirschsprung disease (HD) is characterized by aganglionosis, which mainly occurs in the rectum and distal sigmoid colon. Typical HD is seldom diagnosed in adulthood, and segmental involvement is very rare. A 37-year-old man suffered from refractory constipation for 20 years. He could only defecate once a week and frequently needed an enema for defecation. A barium enema showed an annular stenotic segment of the rectosigmoid colon of 8 cm in length, which started 10 cm above anal circulation and showed dilated colon above the stenotic segment. The distal rectum was normal. The narrowed segment of the rectum was resected. At one-year follow up, the patient had normal defecation without laxatives.