The patient took one capsule every few days at first, and her stool became smooth. Later, the constipation symptoms recurred and gradually worsened, and the patient increased the dosage without authorization and took it for a long time, which became dependent on it. The patient took four pills a day, but still had difficulty in passing stool, and was diagnosed with colonic melanosis after colonoscopy. Colon melanosis is a non-inflammatory disease of the colonic mucosa with lipo-brown pigmentation. The occurrence of colonic melanosis is due to the fact that constipation itself is a factor in the development of colonic melanosis, and the second is that the use of laxatives due to constipation, especially long-term use of anthraquinone laxatives, can lead to the occurrence of colonic melanosis. Studies have shown that the fecal toxins produced by prolonged retention of feces in the colon during constipation can stimulate the intestinal wall to induce apoptosis and be engulfed by phagocytes together with tissue fragments, which are then converted into lipofuscin and deposited in the lamina propria of the intestinal mucosa, which can make the intestinal mucosa darken. Anthraquinone laxatives can also induce apoptosis of colonic mucosal epithelial cells, resulting in the deposition of lipofuscin in the lamina propria, causing the intestinal mucosa to turn black. If long-term constipation is combined with the use of anthraquinone laxatives, it is like “adding insult to injury”, which greatly increases the incidence of colonic melanosis. Therefore, the main point of colon melanosis prevention is to prevent constipation, and to avoid long-term use of laxatives, especially less anthraquinone laxatives. Colonic melanosis is a benign and reversible disease. If you can effectively relieve constipation, timely discontinuation of anthraquinone-based laxatives, in about 1 to 2 years, most patients’ lesions can subside on their own, without special treatment. However, if not taken seriously and laxatives are not detected and discontinued early, the risk of colon cancer will be increased once the lesions continue to develop. Therefore, constipation patients must use medication under the guidance of doctors and avoid long-term use of anthraquinone laxatives. Anthraquinone laxatives mainly include: rhubarb and laxatives containing rhubarb such as rhubarb soda, aloe vera and laxatives containing aloe vera such as compound aloe vera capsules, senna and laxatives containing senna such as laxative capsules, and cassia. Patients with constipation should use these drugs with caution, and should not take them for long periods of time to prevent the risk of cancer caused by colonic melanosis. At the same time, cautioned those long-term drink laxative tea or diet tea for young women, in most of these teas contain anthraquinone laxative, not only may constipation aggravate, but also may suffer from colon melanosis.