1.Specialist examination. (1) visual examination visual examination can be without positive signs, but also with external hemorrhoids and other anal diseases. (2) rectal finger diagnosis rectal prolapse patients in rectal finger diagnosis can be palpated rectal anterior wall circular protrusion to the vagina of the weak area, more obvious when forceful defecation, fingertip feeling intestinal wall tension is reduced, the end of the pointer bowel wall recovery slowly or can not recover. Patients with intra-rectal mucosal prolapse take a squatting or lateral position, do defecation, can touch the folded accumulation of mucosa in the rectal cavity, soft and smooth, moving up and down, with a sense of congestion, and a circular groove between the internal prolapsed part and the intestinal wall. In patients with perineal descent syndrome, the dilatation force of the anal canal is reduced during the resting period, and when the patient is asked to perform random contractions, the contraction force of the anal canal is significantly weakened. Patients with pelvic floor failure syndrome have high anal canal tone and require force to pass through the anal canal. The anal canal is long and the puborectalis muscle is hypertrophic and spastic. The anal canal is contracted instead of relaxed during simulated defecation, which is often called “paradoxical contraction”. (3) In patients with sigmoidoscopy or anorectoscopy, prolapse of the rectal mucosa and perineal descent syndrome can be seen with slight abdominal pressure, and the submucosal accumulation of the rectum can be seen, which seems to protrude into the opening of the lens barrel like a corkscrew. A circular or cervical mucosal infold is seen at the junction of the rectum and anus. Proctoscopy can be seen in the rectal mucosa too much, forceful defecation action can be seen embedded in the mirror cavity or appear below the tooth line, patients can be seen mucosal edema, brittle, congestion, or ulcers, polyps and other lesions. 2.Fecal imaging. Defecography can be used to find out whether there are abnormalities in the anatomical structure of the rectum and anal canal in patients with this disease, so as to screen and guide patients for the next step of surgical treatment and to evaluate the surgical plan. 3.Anal rectal manometry is used to measure the resting pressure, maximum constriction pressure, rectal perception threshold, maximum rectal tolerance and other indicators, which can help to understand the change of anorectal pressure during defecation, and thus assist in diagnosis and evaluation of the treatment effect. 4, colonic transmission test swallowed impermeable X-ray marker – barium strips 20, 72 hours to take X-ray standing abdominal plain film 1, according to the distribution of barium strips on the abdominal plain film to determine the type of constipation. It can help to identify outlet obstruction type constipation, slow transmission type constipation and mixed type constipation. 5.Electromyography can help to identify the type of the disease through this test in order to guide clinical treatment. 6.Balloon forcing out test puts a balloon connected with a catheter into the rectum, fills it with 50ml of warm water and allows the patient to expel the balloon in a normal defecation position. More than 5 minutes is abnormal. This test can help identify incontinence and outlet obstruction type constipation: if the anal sphincter is damaged or no sphincter function, the balloon can slide out of the anus by itself, or the balloon can be expelled after a slight increase in abdominal pressure, then the diagnosis is anal incontinence; if the balloon cannot be expelled for more than 5 minutes, then it is considered outlet obstruction type constipation.