Diseases occurring in the small intestine are collectively known as small bowel diseases, including small bowel bleeding disorders, small bowel inflammatory diseases, ischemic bowel disease, intestinal obstruction, tumors, ulcers and so on. The performance of abdominal pain in different diseases is not exactly the same, there may be severe pain, continuous pain, dull pain, colic, etc., and may also be accompanied by nausea, vomiting and other symptoms. 1. Hemorrhagic disease of the small intestine: mostly seen in the abdomen by trauma, abdominal pain localization is accurate, can be on one side of the abdomen, the pain is severe and persistent, can be aggravated by coughing, changes in body position. 2. Inflammatory diseases of the small intestine: Crohn’s disease, intestinal tuberculosis, typhoid fever, intestinal perforation, etc., most of them are chronic abdominal pain, the pain site is uncertain, vague sensation, mostly discomfort, dull pain and other sensations, often accompanied by nausea, vomiting, sweating and other symptoms. 3. Intestinal ischemic disease: It is a disease in which infarction eventually occurs due to ischemia and hypoxia of the intestinal wall. Abdominal pain manifests itself as sudden onset of severe epigastric pain or periumbilical pain, often accompanied by frequent vomiting and diarrhea. 4. Intestinal obstruction: it can be persistent abdominal distension, and in severe cases, it can be persistent abdominal colic, and in patients with intestinal torsion, the symptoms of abdominal pain can be gradually aggravated, and it is often accompanied by vomiting. 5. Intestinal tumor: there may be no obvious symptoms in the early stage of the tumor, and severe abdominal cramps may occur when the tumor completely obstructs the intestines. 6. Intestinal ulcer: it is mostly manifested as persistent hidden pain in the abdomen, which can’t locate the exact position, and when there is perforation of intestines, there can be severe abdominal pain, accompanied by vomiting. If the patient’s abdominal pain is severe, or accompanied by other symptoms are not relieved, it is recommended to go to the hospital in a timely manner, timely treatment.