Intestinal mucositis, which is also known as the manifestation of congestion, erosion and edema of the intestinal mucosa seen under enteroscopy, is classified into specific inflammation and non-specific inflammation according to the etiology. Abdominal pain, abdominal distension, diarrhea, bloody stools, fever and other symptoms can occur, as follows. 1. Specific inflammation: that is, intestinal inflammation caused by bacterial, viral, fungal and parasitic infections. Patients may have diarrhea, nausea, vomiting, abdominal pain, bloating and other gastrointestinal symptoms. 2. Non-specific inflammation: that is, a group of chronic inflammation of the intestinal tract of unknown etiology, including ulcerative colitis and Crohn’s disease, the specific symptoms are as follows. (1) Ulcerative colitis: recurrent diarrhea, mucopurulent blood stools, vague pain in the left lower abdomen or lower abdomen, nausea and vomiting and other digestive system manifestations may occur, which may also be accompanied by systemic manifestations such as fever, anemia, emaciation and other extra-intestinal damages such as arthritis, oral ulcers and skin erythema. (2) Crohn’s Disease: Patients may have digestive symptoms such as pain in the right lower abdomen or around the navel, diarrhea, mucopurulent blood stools, abdominal masses, perianal abscesses, etc., which may also be accompanied by systemic manifestations such as fever, malaise, weight loss, etc., and even extra-intestinal manifestations such as erythema of the skin, arthritis, and oral ulcers. If the above symptoms occur, it is recommended to go to the hospital in time for early and regular treatment.