On the inner surface of the colon, corresponding to the transverse groove between the colonic pouches, the circular muscle is thickened and the intestinal mucosa is folded into a colonic semilunar fold. The disappearance of the colonic pouch is due to paralysis of the mucosal muscular layer. Early X-ray manifestation of ulcerative colitis is the disappearance of the colonic pouch. How to check the disappearance of colonic pouch half-moon fold? 1.Types According to the clinical manifestations and process can be divided into 4 types. (1) Primary type Symptoms vary in severity, no previous history of ulcerative colitis, can be transformed into chronic recurrent type or chronic persistent type. (2) Chronic relapsing type The symptoms are mild and most common clinically, and there are often periods of remission of varying lengths after treatment. The peak of recurrence is mostly in spring and fall, and less in summer. In the exacerbation period colonoscopy, there are typical ulcerated nodal lesions, while in the remission period, only mild congestion and edema are seen, and the mucosal biopsy is chronic inflammation, which is easy to be mistaken for irritable bowel syndrome. Some patients can turn into chronic persistent type. (3) Chronic persistent type after the onset of the disease often continue to have diarrhea of varying severity, intermittent bloody stools, abdominal pain and systemic symptoms, lasting several weeks to several years, during which there may be an acute attack. This type has a wide range of lesions, progressive colonic lesions, many complications, and severe symptoms during acute attacks, requiring surgical treatment. (4) Acute outbreaks Domestic reports are less, accounting for about 2.6% of the ulcerated knot, foreign reports accounted for 20%. Mostly seen in adolescents, the onset of acute, systemic and local symptoms are serious, high fever, diarrhea 20-30 times a day, the amount of blood in the stool, anemia, dehydration and electrolyte disorders, hypoproteinemia, weakness and emaciation, and prone to toxic colonic dilatation, intestinal perforation and peritonitis, often need emergency surgery, high mortality rate. 2, the main symptoms of diarrhea or constipation, the initial symptoms of the disease is relatively mild, mucus on the surface of the feces, and later increase the frequency of defecation, the heaviest 10-30 times a day defecation, feces is often mixed with pus and blood and mucus, can be paste-like soft stool. Blood in stool is a more common symptom, mainly due to local ischemia of the colonic mucosa and increased activity of dissolved fibrin. Generally, it is a small amount of blood in the stool, and in severe cases, it may be a large amount of blood in the stool or blood-water stool. Abdominal pain is mostly limited to the left lower abdomen or lower abdomen, or no abdominal pain in mild cases, with the development of abdominal pain intensified, and can be relieved after defecation. Inflammation can irritate the rectum, and there is often sacral discomfort. Dyspepsia is often characterized by anorexia, fullness, belching, epigastric discomfort, nausea, vomiting and so on. Systemic manifestations are often seen in acute fulminant severe patients, fever, water-electrolyte imbalance, vitamin, protein loss, anemia, weight loss and so on. 3.Signs Left lower abdomen or the whole abdomen pressure and pain, can be found in the descending colon, especially the sigmoid colon is hard tubular, and there is pressure and pain, sometimes abdominal muscle tension, anal diagnosis can be found in the anal sphincter spasm, the finger sleeve has mucus or bloody mucus secretion, the rectum has tenderness. In some cases, hepatomegaly may be palpable, which is associated with fatty liver.