The etiology of small intestinal tumors is still unclear, and the risk factors for the development of these tumors are currently considered to be poor dietary habits, obesity, and precancerous lesions. It often manifests itself in various digestive symptoms. 1.Etiology: (1) Bad dietary habits: such as high-fat, high-protein, low-fiber diet, smoking, alcoholism, etc., which can lead to DNA damage and increase the incidence of tumors. (2) Obesity: it may promote the occurrence of small bowel cancer. (3) Pre-cancerous lesions: such as familial adenomatous polyposis, Crohn’s disease, celiac disease, ulcers and other diseases, which will progress to cancer if not treated in time. Related gene mutations are associated with the development of small bowel tumors. 2. Symptoms: Small bowel tumor can be asymptomatic in early stage, and various digestive symptoms will appear when the tumor volume is large, the most common symptom is abdominal pain, most patients have recurrent chronic intestinal obstruction, and acute intestinal obstruction can be caused by intestinal intussusception or intestinal torsion. Complicated intestinal obstruction can be manifested as colic, accompanied by diarrhea, nausea and vomiting, dyspepsia and many other symptoms. When the tumor invades blood vessels, gastrointestinal bleeding can occur, and in some patients, the tumor protrudes from the intestinal canal and infiltrates the abdominal cavity, and a mass can be detected on examination, and other symptoms include jaundice, emaciation and other atypical manifestations. Clinical symptoms of small intestine tumor are atypical and it is easy to delay the diagnosis. Therefore, once the above mentioned symptoms occur, patients should seek medical treatment as soon as possible for further examination and clear diagnosis and treatment.