Colonic distention is a common cause of ulcerative colitis (UC), an inflammatory disease of the rectum or colon of unknown origin. It mainly involves the rectum, sigmoid colon and descending colon and is characterized by mucosal congestion, edema, multiple superficial ulcers, advanced wall thickening and luminal narrowing with polyp formation. The disease is characterized by persistent diarrhea, mucus stools, bloody or purulent stools, abdominal pain and urgency, and may be accompanied by extraintestinal manifestations such as fever, anemia, arthritis, skin lesions and liver disease. The onset of the disease is rarely acute, but most of them have a slow onset and a long course, often with recurrent episodes of variable length, also known as chronic non-specific ulcerative colitis. In the early stages, abdominal pain, diarrhea and bloody stools may occur. Abdominal pain of varying degrees is caused by spasm of the colonic muscles, distension of the colon and inflammation stimulating local sensory nerves. Abdominal distension is mostly confined to the left lower abdomen or lower abdomen, with paroxysmal mild pain. When the lesion is severe, it can present colic. 1. Ischemic colitis is an ischemic injury to the colon caused by occlusion of the large and small arteries supplying the colon or insufficient blood perfusion. It is common in hypovolemic shock, heart failure, mesenteric artery embolism or thrombosis, after abdominal aortic reconstruction or aortitis. Acute colonic ischemia is transient and reversible, and in severe cases, total intestinal wall necrosis, perforation or persistent intestinal ischemia occurs in the right. 2, pediatric ulcerative colitis Ulcerative colitis (ulcerative colitisUC), referred to as ulcerative colon, the etiology has not been completely elucidated. It is a chronic non-specific inflammatory disease that mainly invades the mucosa of the colon, often starting from the left hemicolectomy and progressing in a continuous manner to the proximal part of the colon and even the whole colon. The clinical symptoms vary in severity and may alternate between remission and flare-ups. Patients may have only colonic symptoms, but also systemic symptoms. Ischemic colitis in the elderly is damage to the intestinal tract that occurs as a result of obstructive disease of the arteries or branches that innervate the colon, resulting in reduced or absent blood supply to the local intestinal wall. Ischemic colitis is usually spontaneous, with no specific symptoms or signs, and its clinical manifestations vary depending on its severity, extent of involvement, how quickly the ischemic damage occurs, and how well the intestinal wall tolerates hypoxia. It is usually seen in elderly patients over 60 years of age with no previous history of colonic disease who suddenly present with the manifestation of acute abdomen.