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What Is an Anoscopy?

Medically Reviewed by Dan Brennan, MD on April 19, 2021

An anoscopy is a test that allows your doctor to examine the inner lining of your anus and your rectum. The test checks for abnormal growths, bleeding, hemorrhoids, inflammation, and conditions such as diverticulosis

How an Anoscopy Works

Anoscopies are painless procedures that can usually be performed in a doctor’s office within 10-30 minutes.  A lubricated plastic tube called an anoscope is inserted a few inches into the rectum. The anoscope is fitted with a magnifier and a light so your doctor can check for any abnormalities. 

Your doctor may take a tissue sample to perform a biopsy later. This is typically only done if any abnormalities, such as a suspicious growth, are detected during the initial anoscopy. 

What to Expect

Preparation. No preparation is necessary for an anoscopy. However, it is often recommended that you have a bowel movement or empty your bladder to make the procedure more comfortable. If you or your doctor are worried about such a thing, they may provide a laxative or enema to prepare you.

Discomfort. The procedure is painless. You will likely experience feelings of discomfort, pressure, or bloating. You may also feel like you are about to have a bowel movement, but the sensation is normal.  There may be some mild soreness after the procedure. 

Risks. There aren’t any major risks involved with anoscopy. Hemorrhoids, a biopsy, or anal fissures may result in slight bleeding after the procedure. Most side effects will clear up in a few days. 

Why It’s Used

Your doctor may suggest an anoscopy to determine if you have certain conditions. 

Anal Fissures. Anal fissures are slight tears in the lining of the anus. They are typically the result of passing large or hard stools during a bowel movement. Anal fissures cause painful and bloody bowel movements. 

Anal fissures can often be diagnosed based on a physical exam. Chronic anal fissures or tears that have abnormal features, such as being on the side of the anus rather than back or front, can be a sign of an underlying condition. Your doctor may call for an anoscopy to determine such conditions. 

Anal polyps.  Related to colon polyps, anal polyps are growths that form within the lining of the rectum. Most colon or anal polyps are harmless. But if they are left unexamined or untreated, they can eventually lead to colon cancer or rectal cancer. 

Anal polyps typically don’t have symptoms. If you start experiencing rectal pain, bloody stools, or abnormal changes in your bowel habits, contact your doctor at once. To determine the issue, your doctor may suggest an anoscopy. Rectal cancer can often be fatal when found in late stages, so exercising caution and seeking a diagnosis is crucial for recovery. 

‌Hemorrhoids. Hemorrhoids are areas of swollen veins around your anus and rectum. They can be internal and develop inside the rectum, or they can be external and develop under the skin around the anus. Hemorrhoids are common in adults and simple to treat. 

Signs of external hemorrhoids include:

  • Irritation, discomfort, or pain around your anus
  • Swelling around your anus
  • Bleeding

Internal hemorrhoids are harder to detect, and your doctor may schedule an anoscopy to examine them. You typically can’t see or feel internal hemorrhoids. 

Related Procedures

Physical Exams. Prior to any invasive procedures, your doctor will perform a physical exam of the anus and rectum. This involves the doctor typically examining the areas with a gloved lubricated finger for any obvious signs of damage or abnormalities. 

Proctoscopy. A proctoscopy follows a similar procedure to an anoscopy. A flexible tube is inserted into the anus to examine the inside of the rectum and bottom part of the colon. A proctoscopy searches for growths, inflammation, and sources of bleeding. 

While an anoscope is relatively short, a proctoscope is typically around 10-12 inches long. This often requires a laxative or enema to clear the colon beforehand. 

Sigmoidoscopy. A sigmoidoscopy utilizes a thin, flexible tube called a sigmoidoscope. A sigmoidoscope is a 2-foot-long tube with a video camera on the end. It allows your doctor to clearly examine your rectum and the last 2 feet of your large intestine.

A sigmoidoscopy can help your doctor search for intestinal signs of abdominal pain, bleeding, diarrhea, and other intestinal problems. It also is used for older adults to screen for colon cancer, but it’s not the only option. Sigmoidoscopies may be preferred as an alternative to a colonoscopy, as they take less time and fewer resources. 

Results of an Anoscopy

After your anoscopy, your doctor will be able to give you the results right away. It may take several days for a clear conclusion if a biopsy is necessary. Otherwise, it’s business as normal after an anoscopy. 

Show Sources

SOURCES:
Cleveland Clinic: “Proctoscopy (Rigid Sigmoidoscopy).”
Harvard Health Publishing: “Anoscopy.”
MAYO CLINIC: “Anal fissure,” “Colon polyps,” “Flexible sigmoidoscopy,” “Hemorrhoids.”
MICHIGAN MEDICINE: “Sigmoidoscopy (Anoscopy, Proctoscopy).”
MOFFITT CANCER CENTER: “Anal Cancer Diagnosis.”
UFHealth: “Anoscopy.”
Wake Forest Baptist Health: “High Resolution Anoscopy.” 

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