The anoscope is a specialized medical tool designed for the direct, visual examination of the anal canal and the lower section of the rectum. This rigid, tube-like instrument allows a healthcare provider to safely inspect the lining of the final few inches of the digestive tract in an office setting. The procedure, known as anoscopy, is performed to investigate symptoms such as pain, bleeding, or itching in the anal region. It provides immediate diagnostic information without the need for extensive preparation or sedation.
Defining the Instrument
The anoscope is a short, hollow tube, typically measuring three to five inches in length and one to two inches in diameter. This instrument is often referred to as an anal speculum. It is constructed from either reusable stainless steel or disposable translucent plastic. The design includes a smooth, tapered tip to facilitate gentle insertion.
A removable obturator is initially placed inside the tube to keep the tip smooth during insertion. Once the instrument is fully in place, the obturator is withdrawn, leaving the hollow tube to provide an open channel for viewing. Illumination is provided by an external light source or a small light built directly into the disposable models, allowing the clinician to clearly see the tissue lining.
Primary Medical Uses
The anoscope is frequently employed to identify swollen veins, known as internal hemorrhoids, a common cause of bleeding and discomfort. The instrument is also used to locate anal fissures, which are small tears in the lining of the anal canal that cause sharp pain during bowel movements. The anoscope further aids in the detection of anal polyps or other abnormal growths on the lining.
If a suspicious area is noted, the anoscope offers a working channel through which a clinician can collect a small tissue sample for laboratory analysis, a process called a biopsy. Specialized slotted anoscopes are also used to perform therapeutic procedures like rubber band ligation, which treats internal hemorrhoids by cutting off their blood supply.
What to Expect During the Exam
Preparation for an anoscopy is minimal, often requiring only that the patient empties their bladder and bowels shortly before the procedure. Unlike procedures like a colonoscopy, no special bowel preparation is needed. The healthcare provider will position the patient, often asking them to lie on their side with their knees drawn toward the chest (the fetal position) or to bend over the examination table.
The clinician first performs a digital rectal exam using a lubricated, gloved finger to check for any obvious masses or tenderness. The anoscope, coated with a lubricating jelly, is then inserted gently a few inches into the anus. During insertion, the patient may be asked to relax the internal muscles to ease the passage of the instrument.
The entire examination is very quick, often lasting only a minute or two. The most common sensation is pressure or fullness, though it should not be painful. If the patient has a painful condition like a fissure, a numbing gel may be used beforehand. After the instrument is gently removed, the patient can usually resume normal activities immediately.