In general, there is a relationship between colon blackening and long-term medication. Colonic black change, that is, colonic black change disease, is due to a large number of lipofuscin-like substances in the macrophages within the lamina propria of the colon, mucosal pigmentation leads to darkening of the colon, which is a kind of benign, self-recovery non-inflammatory bowel disease. Blackening of the colon of varying degrees is visible under colonoscopy, and patients mainly present with digestive symptoms such as constipation, bloating, diarrhea, and abdominal pain. Long-term oral laxatives such as senna and other anthraquinones, bisacodyl and other drugs to improve constipation, these drugs can promote the death of intestinal epithelial cells, the dead cells are phagocytosed by macrophages and converted into lipofuscin and other pigments, deposited in the colonic mucosa and make it appear black. In addition, advanced age, intussusception, ulcerative colitis, etc. can also induce colonic melanosis. Patients with colonic melanosis are advised to seek prompt medical attention for diagnosis and targeted treatment.