Pigmentation Sparing on Melanosis Coli

Abstract

Question: A 91-year-old man visited our outpatient clinic because of chronic constipation for decades and more recent tenesmus. For the chronic constipation, he had been taking sennosides laxatives for 40 years. The colonoscopy showed diffuse, dark brown pigmentation throughout the colon, which is grossly consistent with melanosis coli. One polypoid lesion of 1.5 cm (Figure1 A) seemed pale, with some flat tiny foci (Figure B) devoid of pigmentation in the descending colon. These lesions were underwent endoscopic submucosal resection.