The examination of the anus and rectum is commonly performed using anoscopy or proctoscopy. These minimally invasive procedures allow a physician to visually inspect the lining of the anal canal and the lower section of the rectum. The procedures are relatively quick and are typically performed in an outpatient clinic or a doctor’s office setting, providing direct visual access for investigating localized symptoms and diagnosing a variety of conditions.
Identifying the Core Procedure
The two primary localized procedures are anoscopy and proctoscopy, distinguished mainly by the depth of the examination. Anoscopy uses a short, rigid instrument called an anoscope to view the anal canal, the final section before the anal opening. This instrument is usually only a few inches long, allowing for a focused inspection of the most distal area of the gastrointestinal tract.
Proctoscopy utilizes a slightly longer, rigid tube called a proctoscope to examine the anal canal and extend into the rectum. The rectum is the final chamber of the large intestine, and the proctoscope can visualize its lower portion. Both devices are essentially hollow tubes equipped with a light source and a lens, enabling the physician to look directly at the tissues and internal structures.
A physician may recommend these focused exams to investigate symptoms such as unexplained rectal bleeding, persistent pain near the anus, or chronic issues like diarrhea or constipation. These procedures are useful for identifying common localized issues like hemorrhoids, anal fissures, or abscesses. Furthermore, they can aid in the detection of polyps, inflammation, or early signs of anal or rectal cancer, and can be used to monitor previously treated conditions.
Preparation and Steps of the Examination
Preparation is often minimal, particularly for anoscopy, which may require no special steps. For a proctoscopy, the physician may ask the patient to use a localized enema or glycerin suppository shortly before the procedure. This cleansing helps to clear the rectum and ensure the clearest possible view of the tissues. Dietary restrictions or the use of oral laxatives are generally not necessary.
During the procedure, the patient is typically asked to lie on their side with their knees drawn toward their chest or to lean over an examination table. This positioning allows the doctor easier access to the anal region for the examination. The physician first performs a digital rectal exam by inserting a lubricated, gloved finger into the anus to check for any obvious abnormalities or areas of tenderness.
Following the finger examination, the lubricated anoscope or proctoscope is gently inserted into the anal canal. Anesthesia is not typically required, as the procedure usually takes only about 10 to 20 minutes to complete. The patient may feel a sensation of pressure or fullness, similar to needing a bowel movement. The scope may also be used to remove small polyps or to collect a tissue sample for a biopsy if an abnormal area is observed.
Clarifying Related Diagnostic Scope
Anoscopy and proctoscopy are distinct from other endoscopic procedures that examine a larger portion of the gastrointestinal tract. A sigmoidoscopy uses a longer, flexible tube to examine the rectum and the sigmoid colon, the S-shaped part of the large intestine just above the rectum. The flexible nature of the sigmoidoscope allows it to navigate the curves of the colon, extending the diagnostic reach beyond the proctoscope.
The most extensive examination is a colonoscopy, which uses an even longer, highly flexible tube to inspect the entire length of the large intestine, including the colon and the rectum. A physician chooses a sigmoidoscopy or colonoscopy when the symptoms suggest a problem higher up in the colon, or for general colorectal cancer screening. Unlike the localized procedures, a full colonoscopy requires a complete bowel preparation using strong laxatives and often involves sedation.
The different procedures are chosen based on the suspected location and nature of the problem. A proctoscopy is sufficient for diagnosing conditions like hemorrhoids, which are close to the anal opening, while a colonoscopy is the standard for detecting polyps throughout the entire colon. The localized exams are much shorter and require less preparation.