Colonic redundancy is the result of overgrowth of the colon due to genetic reduplication during development. It is most commonly seen in the sigmoid colon, followed by the transverse colon. The human colon is about 150 cm long, of which the ascending colon is about 15 cm, the transverse colon about 55 cm, the descending colon about 25 cm, and the sigmoid colon about 40 cm. If a barium enema shows that a segment of the colon is longer than 40% of its normal length, it is considered to be colonic redundancy. The submucosal plexus and intermuscular plexus of the diseased intestinal segment are significantly hyperplastic, and the number of ganglion cells is significantly increased. There is also a possibility of NOergic nerve disorders in the intestine. Idiopathic intractable constipation due to colonic redundancy occurs mainly in children and in middle-aged and elderly people over 40 years of age (more common in women). In children, the onset of constipation can be as early as 6 months after birth, and most of them develop symptoms after 3 years of age, usually having a bowel movement once every 4-6 days, with the longest being once every 15 days. Children have significant abdominal distension and intermittent abdominal pain, mostly caused by redundant sigmoid colon. The history of constipation in middle-aged and elderly people can be as long as 10 years, gradually worsening, and some patients have had acute intestinal obstruction several times. Patients often have a long history of taking stimulant laxatives. Generally 4-15 days to defecate once, some even long-term no intention to defecate, must regularly use laxatives before defecation. The diagnosis mainly relies on barium enema: the upper edge of the midpoint of normal transverse colon is between vertebrae T11 and S1 in the horizontal position, and descends by an average of 2 vertebrae in the vertical position. In contrast, the superior border of the midpoint of the redundant transverse colon is below L3 in the horizontal position and drops by 4 vertebrae in the vertical position, often below S3 or below the level of the sacroiliac joint. The normal sigmoid colon should be sigmoid or linear below the level of the left iliac crest, and its tethered root is usually below the line between the left anterior superior iliac spine and the sacral promontory. In contrast, the redundant sigmoid colon clearly protrudes into the right lower abdomen and shows curved extension, distortion, and in some cases, a circular loop. Treatment of redundant colon: 1, general treatment: including active regulation of diet and bowel habits, biofeedback therapy, taking intestinal dynamics promoters, flora regulating preparations, volumetric laxatives and herbal preparations without irritating laxatives, but try not to use irritating laxatives containing anthraquinones, and if necessary, enema therapy is also feasible. 2.Surgical treatment. Indications: 1, the patient has a typical history of intractable constipation, the number of bowel movements is less than 1 time/week; 2, barium enema confirmed that the sigmoid colon is long, curved and tortuous; 3, the systemic conservative treatment is ineffective, the history of more than 1 y; 4, there is an acute intestinal obstruction, intestinal torsion requires emergency treatment; 5, the patient has a strong demand for surgery. Purpose: To remove the diseased intestinal segment, deal with the corresponding complications and restore normal intestinal peristalsis.