A lower gastrointestinal endoscopy is a common medical procedure that allows healthcare providers to examine the lower part of the digestive tract. This examination relies on a specialized instrument designed to navigate the intricate pathways within the body. The development of this instrument has significantly advanced the ability to visualize and address conditions affecting the colon.
The Colonoscope
The primary instrument for lower gastrointestinal endoscopy is the colonoscope. This long, flexible tube, typically 130 to 180 centimeters in length and 12 to 13 millimeters in diameter, allows for careful insertion and maneuverability within the colon. The colonoscope is equipped with a light source and a miniature camera at its tip, which transmit images to a monitor for the physician to view.
Components and Functionality
At its distal tip, a miniature camera or fiber optics capture detailed images, while a powerful light source illuminates the internal environment. The instrument also contains an air/water channel, which allows the physician to inflate the colon with air for better visualization and to spray water to clear debris or clean the lens. A separate suction channel removes fluids, mucus, or small amounts of stool, ensuring a clear field of view. All these functions, along with the ability to steer the tip, are controlled by the physician through a dedicated control section, often referred to as the handle, located at the external end of the instrument.
Interventional Capabilities
Beyond visual inspection, the colonoscope serves as a conduit for various medical interventions. It features a working channel, a narrow passage running the length of the scope, through which specialized tools can be introduced to perform procedures directly within the colon.
For instance, tiny forceps obtain tissue samples (biopsies) for laboratory analysis. Wire loops called snares remove polyps, abnormal growths on the colon lining, in a procedure called polypectomy. The working channel also allows for the delivery of devices that can stop bleeding (hemostasis).
Related Endoscopic Instruments
While the colonoscope is used for a full examination of the large intestine, the sigmoidoscope focuses on a specific segment. A sigmoidoscope is similar in design but considerably shorter, typically 60 to 70 centimeters long. This shorter length allows it to examine only the lower part of the large intestine: the rectum and sigmoid colon. Sigmoidoscopy is used for targeted issues or certain screening purposes when a full colonoscopy is not required.