The diagnosis of small bowel cancer mainly relies on clinical manifestations, imaging and other examinations. Clinical symptoms may manifest as abdominal pain, intestinal bleeding, intestinal obstruction, intestinal perforation and so on. Imaging examination includes X-ray barium meal examination, abdominal CT, etc. Fiber duodenoscopy, capsule endoscopy, fiber small bowel microscopy, selective arteriography, etc. can also be chosen to improve the diagnosis rate. For those with elevated 5-hydroxytryptamine, its degradation should be measured in urine to help determine the nature, dissection, etc. There is no easy way to diagnose small bowel cancer, and the diagnosis of the disease usually requires a variety of indexes pointing to it, therefore, you should consult a doctor in time when you feel unwell, and under the guidance of a professional doctor, you should make a clear diagnosis and choose an appropriate treatment to maximize the quality of life.