Colitis, also known as non-specific ulcerative colitis, often starts slowly and varies in severity. Diarrhea is the main symptom, with pus and bloody stools, bloody mucus or bloody stools, often accompanied by tenesmus, abdominal pain and the urge to defecate. → Defecation → Relief characteristics of colitis abdominal pain is usually dull pain or colic, often located in the left lower abdomen or lower abdomen. Other symptoms include loss of appetite, abdominal distension, nausea, vomiting, and hepatomegaly; there may be tenderness in the left lower abdomen, and sometimes the spasmodic colon can be touched. Common systemic symptoms include weight loss, fatigue, fever, anemia, etc. In the chronic course of the disease, a small number of patients suddenly worsen or become fulminant at the first onset, exhibiting severe diarrhea 10-30 times a day, excreting feces containing blood, pus, and mucus, as well as high fever, vomiting, and tachycardia. Rapid disease, failure, dehydration, electrolyte imbalance, coma and even colon perforation can cause death if not treated in time.