The cause of the disease is not completely clear, and the following factors are related to the disease.
1, anatomical factors
In children with sacrococcygeal uplift, the rectum is vertical, the abdomen is compressed, and rectal prolapse is lack of support. The low retroperitoneum of rectocele is caused by the pressure in abdominal cavity and the pressure of intestinal loop on the anterior wall of rectum on the ampulla of rectal prolapse. Muscle relaxation in the elderly, perineal tear during childbirth or childbirth can also cause rectal prolapse.
2. Increased intra-abdominal pressure
Long-term constipation, diarrhea, chronic cough and dysuria can cause the increase of intra-abdominal pressure and rectal prolapse. In recent years, foreign studies have found that rectal prolapse is often accompanied by mental or nervous system diseases, and the relationship between them is still unclear. Some people think that when the nervous system is diseased, the function of controlling and regulating defecation is impaired, the rectum is chronically dilated, and the sensitivity to fecal stimulation is weakened, resulting in constipation and decreased ability to control defecation. Abnormal exertion during defecation weakens the function of levator ani and pelvic floor tissue, which is also a common cause of rectal prolapse.
3. System factors
In malnourished children, the fat in the ischiorectal fossa disappears, which makes the rectum lose its peripheral support and fixation function, and the contractility of sphincter groups is also weakened, which makes the rectum easily protrude from the anal orifice.
4, local tissue anatomical factors
① The sacrum is not bent, and the pelvis is not forward enough for the baby. In the upright position, the pressure in the rectum, anal canal and abdominal cavity increases, and the rectum has no sacral support, so the pressure directly acts on the anal canal and it is easy to slide down.
② The supporting force of peripheral muscles is weak, and that of levator ani and pelvic floor muscles is weak.
③ Mucosal relaxation, the adhesion between rectal mucosa and muscularis is relatively loose, and the mucosa is easy to slip from muscularis.
5. Causes
Any long-term or sudden increase in intra-abdominal pressure will lead to rectal prolapse. Such as frequent constipation, diarrhea, whooping cough, phimosis and bladder stones, long-term chronic cough and other diseases, are often the causes of proctoptosis. Some diseases such as lumbosacral spinal meningocele or injury, including accidents and surgical injuries, cause dysfunction of sphincter around rectum and muscle or nerve function, rectal prolapse can occur when rectum loses support and abdominal pressure increases.
6. Others
Surgical trauma caused lumbosacral nerve paralysis, anal sphincter relaxation and rectal mucosal prolapse.