Anorectal complaints may be due to benign anorectal disorders or malignancy. Common symptoms include pain, swelling, discharge, and rectal bleeding. Systemic symptoms and changes in bowel movements may also occur.
One useful way of classifying benign anorectal disorders is to divide them into those that cause pain and those that do not. Common painful anorectal conditions include anorectal abscess, anal fissure, and thrombosed external hemorrhoids. Common painless anorectal conditions include fistula in ano and symptomatic internal hemorrhoids.
Diagnostic studies to investigate anorectal disorders include assessment of the perineum, digital rectal examination, and anoscopy or sigmoidoscopy. Other studies that are sometimes necessary include transrectal/endoanal ultrasonography (evaluation of the structure of and defects in the anal sphincter), anal manometry (evaluation of anal sphincter function), and magnetic resonance imaging (MRI).