&NA;While spontaneous amputation of colonic polyps occurs frequently in children with juvenile polyps, such autoamputation is rare in adults. Two cases of autoamputation of colonic polyps are reported here: in one, the passage of a polypoid papillary adenocarcinoma, 2×3 cm, was accompanied by cramps, severe bleeding and syncope; in the other, a benign adenomatous polyp, 2×3 cm, was passed with no accompanying symptoms.