Anoscopy Health Article

Definition

Anoscopy is a diagnostic procedure that allows a gastroenterologist or other physician to visually examine the rectum, anus, and anal canal.

Purpose

Doctors use anoscopy to diagnose rectal cancer and cancer of the anus. This procedure can also help the doctor:

• detect any lesions that could not be felt during a digital examination
• determine whether squamous cell carcinomas involving lymph nodes in or near the groin (inguinal lymph nodes) originated in the genital area or in or near the anus or rectum
• confirm the source of malignancies that have spread to the anorectal area from other parts of the body

Doctors also perform anoscopy to determine whether a patient has hemorrhoids or anal:

• growths or nodules (polyps)
• ulcer-like grooves (fissures)
• inflammation
• infection

Description

After removing underwear, the patient bends forward over the examining table or lies on one side with knees drawn up to the chest. The doctor performs a digital examination to make sure no tumor or other abnormality will obstruct the passage of a slender lubricated tube (anoscope). As the doctor gently guides the anoscope a few inches into the rectum, the patient is told to bear down as though having a bowel movement, then relax.

By tensing and relaxing, the patient makes it easier for the doctor to insert the anoscope, and discover growths in the lining of the rectum that could not be detected during the digital examination.

Directing a light into the anoscope gives the doctor a clear view of any tears or other irregularities in the lower anus or rectum. A doctor who suspects that a patient may have cancer will remove tissue for biopsy in the course of this procedure.

Slowly withdrawing the anoscope allows the doctor to thoroughly inspect the entire anal canal. As the procedure is being performed, the doctor explains what is happening, and why the patient feels pressure.

Removing tissue samples for biopsy can pinch, but anoscopy does not usually cause pain. Patients do experience the sensation of needing to have a bowel movement.

Preparation

The rectum should be emptied of fecal matter (stool) before the procedure is performed. The doctor may suggest using:

• a laxative,
• an enema,
• or some other preparation

to clear the recturn