An adult presented with chronic constipation and abdominal mass. Clinical features, abdominal radiographs and barium enema revealed features consistent with Hirschsprung's disease. Full-thickness rectal biopsy was planned, but patient was lost to follow-up and presented 3 years later with intestinal obstruction. Exploratory laparotomy with resection of affected sigmoid colon and end colostomy were performed. Sequential rectal biopsies were obtained during the procedure to confirm the diagnosis. Later, Duhamel's procedure with a diverting loop ileostomy was successfully performed. Ileostomy reversal was done thereafter. There was complete resolution of symptoms and dramatic improvement in bowel function.