Ulcerative colitis is an inflammatory process confined to the mucosa and submucosa of the colon. The disease is mostly located in the sigmoid colon and rectum, but may also extend to the descending colon or even the entire colon. The pathology is long and often recurrent. The disease is seen in any, but is most common in 20-30 years of age. The lesions are located in the large intestine and have a continuous diffuse distribution. Most are in the rectosigmoid colon and may extend to the descending colon, transverse colon, or involve the whole colon. The active mucosa shows a diffuse inflammatory response. Diffuse lymphocyte, plasma cell, monocyte and other cellular infiltrates in the intrinsic membrane are the basic lesions of UC, and there is a large number of neutrophil and eosinophil infiltrates in the active phase. A large number of neutrophil infiltrates occur in the lamina propria, crypt epithelium (cryptitis), intracrypt (crypt abscess), and surface epithelium. When the crypt abscesses fuse and ulcerate, the mucosa appears as extensive small ulcers that may gradually fuse into large ulcers. Visually, the mucosa is seen to be diffusely congested and edematous with a finely granular surface, increased friability, erosion and ulceration. Because colonic lesions are generally limited to the mucosa and submucosa and rarely penetrate into the muscular layer, complications of colonic perforation, fistulas or peripheral abscesses are rare. In a few fulminant or severe cases, the lesions involve the whole colon, and toxic megacolon may occur, with heavy congestion of the intestinal wall, enlargement of the intestinal lumen, thinning of the intestinal wall, and ulcers involving the muscular to plasma layers, often complicated by acute perforation. If there is no timely treatment of ulcerative colitis may lead to the occurrence of the following conditions: 1. Perforated intestine perforation is often caused by toxins or improper medication. The perforation often causes peritonitis, which is a serious condition; 2. blood in the stool is caused by the destruction of the intestinal mucosa and injury to blood vessels, and long-term blood in the stool can cause anemia, which can lower the patient’s resistance; 3. intestinal blockage in patients with ulcerative colitis, the intestinal muscle layer thickens and pseudo-polyps form, which can cause partial or complete blockage and intestinal obstruction, especially in patients with serious and long duration of the disease; 4. cancerous changes in the intestine of patients with this disease The chance of carcinoma is 2.5 to 4 times greater than normal, mostly seen in patients with more than 10 years of disease. Therefore, patients with this disease are targeted for surveillance of cancer in the large intestine, so that early detection of bowel cancer can be achieved; 5.