A colonoscopy is a medical procedure used to examine the large intestine. It detects changes or abnormalities like inflammation, polyps, or early signs of colorectal cancer. It serves as a routine screening tool for individuals over 50 or those with specific symptoms like changes in bowel habits, abdominal pain, or unexplained bleeding. Direct visualization of the intestinal lining aids in diagnosis and removal of suspicious growths.
The Colonoscope: How it Works
The colonoscope is a long, flexible tube, approximately 130 to 170 centimeters in length and about 12 to 13 millimeters in diameter, designed to navigate the twists and turns of the large intestine. Its tip houses a tiny camera, which captures real-time images of the colon’s interior. Fiber optic cables run through the scope to deliver a bright light, illuminating the pathway for clear visualization.
The insertion tube, which is the main body of the colonoscope, is highly flexible yet firm enough to be maneuvered through the colon. A control section, located at the operator’s end, features dials and levers that allow the physician to steer the tip of the scope in various directions—up, down, left, and right—with precise movements. This steering mechanism helps the physician navigate the colon’s contours and obtain optimal views of the mucosal lining.
The colonoscope also contains multiple internal channels. One channel is dedicated to transmitting the live video feed from the camera to an external monitor. Other channels allow for the insufflation of air or carbon dioxide to gently expand the colon, providing a better view of the walls. A separate channel facilitates the suction of fluids or debris, clearing the field of vision. Furthermore, a working channel allows for the insertion of specialized instruments to perform biopsies or remove polyps during the procedure.
Essential Accessories and Their Purpose
During a colonoscopy, several specialized tools are passed through the colonoscope’s working channel to perform various diagnostic and therapeutic tasks. These accessories are designed to be thin and flexible enough to navigate the scope’s internal pathway. Each tool serves a specific purpose, allowing for comprehensive examination and intervention.
Biopsy forceps are small, pincer-like instruments used to collect tissue samples from the colon lining. These samples are then sent to a laboratory for microscopic examination to identify any abnormal cells or confirm diagnoses. Polypectomy snares are wire loops that can be tightened around polyps to remove them. An electrosurgical current is often applied through the snare to cut the polyp and cauterize the tissue, minimizing bleeding.
Hemostatic clips are tiny, mechanical devices deployed through the scope to stop bleeding. They are used to close small blood vessels or tissue tears that may occur during polyp removal or biopsy. These clips remain in place for a few days to weeks until the tissue heals, then naturally detach and pass out of the body.
Support Systems for a Clear View and Safe Procedure
Beyond the colonoscope and its direct accessories, several external support systems are necessary to ensure a clear view and the safety of the patient during the procedure. These systems work in conjunction with the colonoscope to facilitate a successful examination. The video monitor is a central component, displaying the high-resolution images captured by the colonoscope’s camera in real-time.
An insufflator is used to introduce air or carbon dioxide into the colon, gently expanding its walls. This expansion helps to flatten the folds of the colon, allowing the physician to better visualize the entire mucosal surface and identify any abnormalities. Carbon dioxide is often preferred because it is absorbed more quickly by the body than air, which can reduce post-procedure discomfort for the patient.
A suction pump is connected to the colonoscope’s suction channel, allowing the physician to remove any liquid, stool residue, or blood that might obstruct the view. Maintaining a clear field of vision is important for accurate diagnosis and safe manipulation of instruments. A water jet system is also integrated, which allows the physician to spray water through a channel in the scope to clean the camera lens or rinse off any adherent debris on the colon wall, further enhancing visibility.