Colonoscopy can also check internal hemorrhoids. Colonoscopy is used to examine the large intestine, including the colon and rectum. When an experienced colonoscopist or anorectal surgeon performs a colonoscopy, he or she can turn the lens upside down by 180 degrees when it comes to the anal opening, and then perform an examination of internal hemorrhoids or the localization of the anal canal. So the colonoscopy is not only to check the intestinal canal, but also to check the localization of the anal canal. Of course, after the colonoscopy should be done with the anal fingerprinting, so as not to miss the diagnosis, only patients with blood in the stool after the colonoscopy can be 100% sure that the bleeding is internal hemorrhoids. Patients with blood in stool, especially those of advanced age and with a family history of intestinal tumors, should undergo colonoscopy as early as possible to rule out bleeding in the intestines.