Prolapse refers to the prolapse of the anal canal, rectum or even sigmoid colon out of the anus. Most of the children can heal by themselves, some of them can be treated by injection therapy, and very few of them need to be treated by surgery. Causes: 1, congenital; 2, acquired: malnutrition, wasting, long-term disorders of the defecation process, fibrosis of the bladder (often coexisting with loose tissue of the pelvic floor), abnormal increase in abdominal pressure, long-term unbalanced diet, etc.