Colorectal melanosis

　　The etiology of colorectal melanosis is still not clear, but its incidence has shown an increasing trend in recent years, which may be related to the improvement of living standards, increased intake of fat and protein, reduced intake of fiber, an increase in the number of constipation patients, and difficulty in defecation due to rectal prolapse, intussusception of the rectum, and a slower colonic transport function, as well as the excessive use of laxatives. Especially anthraquinone laxatives are the main cause of melanosis.

　　Patients with colorectal melanosis often have abdominal distension, constipation, and difficulty in defecation; a few patients have hidden abdominal pain and poor appetite. Colorectal melanosis can also lead to complications such as intestinal obstruction, poor digestion, and electrolyte metabolism disorders.

　　Patients with colorectal melanosis often have abdominal distension, constipation, and difficulty in defecation; a few patients have hidden abdominal pain and poor appetite. In the past, melanosis has invaded the enteric plexus, causing degenerative changes in the mucosal plexus, and it is believed to be related to electrolyte disorders as well.

　　To prevent colorectal melanosis, one should eat more vegetables, fruits, and other fiber-rich foods, drink plenty of water, exercise regularly, and reduce constipation or difficulty in defecation. For diseases that cause difficulty in defecation, such as rectal prolapse, intussusception of the rectum, and puborectalis syndrome, appropriate treatment measures should be taken, such as rectal prolapse repair, intussusception fixation surgery, and partial resection of the puborectalis muscle, in order to restore normal defecation and prevent the excessive use of laxatives, which is an effective method for the prevention and treatment of melanosis.

　　The diagnosis of melanosis coli and rectum relies not only on clinical manifestations but also on laboratory tests and auxiliary examinations, which are indispensable means. The specific tests are as follows:

　　1. Blood biochemistry test
　　Generally normal, a few patients mainly show symptoms such as low sodium, low potassium, and low calcium.

　　2. Endoscopic examination
　　The colonic mucosa shows varying degrees of pigmentation. It is divided into three degrees according to the depth of pigmentation: Grade I is light brown, similar to leopard skin, with asymmetrical milky white spots visible on the lymphoid follicles, and the mucosal blood vessels are faintly visible. The lesions mostly affect the rectum or cecum, or a certain segment of colonic mucosa, and the range of involved colonic segments is usually small, and the boundary between mucosa with pigmentation and mucosa without pigmentation is usually not clear; Grade II is dark brown, with linear milky white mucosa between dark brown mucosa, mostly seen in the left half of the colon or a certain segment of colonic mucosa, and the mucosal blood vessels are not easily seen. The boundary between mucosa with pigmentation and mucosa without pigmentation is relatively clear; Grade III is dark brown, with fine milky white lines or spots between dark brown mucosa, and the mucosal blood vessels are invisible, which is mostly seen in the whole colon type. The lesions do not affect the ileal mucosa, and the mucosa of the ileocecal valve is usually not affected. The skin of the anal canal below the anal vermillion line does not show pigmentation. It is generally believed that the pigmentation of the colonic mucosa in colorectal melanosis is most common in the cecum.

　　In addition to conventional Western medical treatment, patients with melanosis coli and rectum should also pay attention to the following aspects in diet: cultivate correct defecation habits, drink more water, eat more high-fiber foods, and avoid spicy foods.

　　In the treatment of melanosis coli and rectum, there have been reports of patients with melanosis coli and rectum who have been taking laxatives for a long time due to anterior rectal prolapse and intussusception. After rectal prolapse repair and intussusception fixation surgery, defecation is normal. One year after stopping the use of laxatives, the melanosis has disappeared. However, the treatment methods for patients with melanosis coli and rectum without taking laxatives still need to be further discussed in combination with medical history, dietary habits, lifestyle, and other characteristics.