Anal finger examination is a routine examination in anorectology. In China, about 75% of rectal cancers are detected by anal examination, so it is very important to detect early rectal and anal canal tumors, and this routine examination should not be neglected. The indications of anal finger diagnosis: 1.Blood in stool or progressive aggravation; 2.Recurrent bleeding of hemorrhoids; 3.Mucus stool or purulent stool; 4.Change of bleeding volume and color; 5.Dark blood in stool mixed with stool, or puddle-like bleeding and blood clots; 6.Change of defecation habit, thin stool and difficulty in defecation; 7.Anal swelling and pain in sacro-caudal region; 8.Anal relaxation than before; 9.Anal overflow and urination; 10. Anal overflow and abnormal urination; 10. Long-term abdominal distension, abdominal pain or diarrhea; 11.