Anus

Also posterior yīn; lower extreme; corporeal soul gate. The lower opening of the large intestine through which stool is discharged.

Diagnosis: A burning sensation in the anus during defecation is a sign of large intestine damp-heat. Bleeding from the anus can be attributed either to hemorrhoids or to splitting of the anus by the passage of hard stool in blood heat intestinal dryness patterns. Diseases of the anus include anal fistula; anal welling-abscess; hemorrhoid; splitting of the anus; prolapse of the rectum.