Idiopathic mesenteric phlebosclerosis (IMP) is a rare ischemic colitis characterized by calcification of mesenteric veins and submucosal veins of the colon. Melanosis coli (MC) is a pigmented mucosal lesion comprising macrophages in the lamina propria of the colorectal mucosa that contain lipofuscin. This study reports a case of IMP combined with MC.Clinicians should consider medication history, bowel preparation, and thorough observation to prevent missed IMP diagnosis when coexisting with MC.