Resection of an anal fistula with endoscopic submucosal dissection.

A 34-year-old man presented with paroxysmal hypogastralgia during defecation for 2 weeks. Physical and laboratory examination findings were unremarkable, other than a depression located 1 cm above the dentate line, accompanied by mild tenderness and a clubbed induration extending to the rectum. Colonoscopy showed a 2.