Bowel examination mainly includes the following: 1. Anal finger examination and anorectoscopy, which are relatively simple, convenient and economical, and can be performed after the patient has defecated, and can generally detect diseases of the rectal area, such as hemorrhoids, rectal polyps and rectal cancer; 2. Colonoscopy, which is the most common and intuitive way to examine the intestines, but is a bit complicated to prepare. Patients are required to take laxatives and perform intestinal cleansing before undergoing colonoscopy. If the patient has fear of psychology or fear of pain, after assessment, painless colonoscopy can be considered; 3, X-ray barium meal imaging is also more commonly used, mainly through the development of a certain diagnosis, not as intuitive as colonoscopy, but also has the advantage of looking at the relationship between the periphery and the outside world, as well as the association with the outside organs; 4, if for various reasons, the patient can not accept invasive examination, you can choose to do abdominal CT or MRI; 5, small intestinal microscopy, capsule endoscopy; 6, laboratory tests, such as blood routine, stool OB test or tumor marker test, etc.