Gastroenterologists are the medical specialists primarily responsible for performing colonoscopies. Their expertise centers on the entire gastrointestinal (GI) tract, including the esophagus, stomach, small intestine, colon, and rectum. The colonoscopy allows them to visualize the lower GI tract to diagnose and manage a wide range of conditions.
Defining the Gastroenterologist’s Expertise
A gastroenterologist, often called a GI doctor, specializes in the digestive system and performs colonoscopies. This specialization requires a demanding training path following four years of medical school. After completing a three-year residency in internal medicine, doctors undergo an additional two to three years of specialized fellowship training in gastroenterology.
This extensive fellowship focuses on diagnosing and treating conditions affecting the GI tract, liver, pancreas, and gallbladder. A large component of this training involves mastering complex endoscopic procedures, such as colonoscopy and upper endoscopy. The American Society for Gastrointestinal Endoscopy recommends trainees perform a minimum of 275 colonoscopies to achieve competency.
This training ensures the physician possesses the technical skill to maneuver the scope and the cognitive skill to interpret findings and manage pathology. Their expertise covers diseases like inflammatory bowel disease (IBD), gastroesophageal reflux disease (GERD), and liver disorders. General practitioners typically refer patients to this specialist for definitive endoscopic diagnosis and intervention.
The Colonoscopy Procedure
A colonoscopy is a medical procedure used to examine the lining of the large intestine (colon) and the rectum. The examination uses a long, flexible tube called a colonoscope, which has a light and a miniature camera at its tip. The scope is gently inserted through the rectum and advanced through the entire length of the colon.
The primary purpose is colorectal cancer screening, which involves looking for and removing precancerous growths called polyps. Polyps are abnormal tissue masses that can develop into cancer if left untreated. During the procedure, the doctor can remove these polyps using specialized tools passed through the scope, a process known as a polypectomy.
The procedure is typically performed under conscious sedation or deeper anesthesia for patient comfort, lasting approximately 30 to 60 minutes. Screening colonoscopies are performed on asymptomatic individuals to prevent cancer, usually starting at age 45 for average-risk patients. Diagnostic or therapeutic colonoscopies investigate symptoms like bleeding or chronic abdominal pain, or follow up on past findings.
Essential Patient Preparation
Successful completion of a colonoscopy depends heavily on the patient’s adherence to the bowel preparation, or “prep,” instructions. The goal of the prep is to completely clear the colon of stool and residue for an unobstructed view of the lining. Remaining fecal matter can hide small polyps, compromising the test’s accuracy and potentially requiring a repeat procedure.
Preparation typically begins with a low-residue or low-fiber diet for three to five days before the procedure, avoiding foods like nuts, seeds, and raw fruits and vegetables. The day before the colonoscopy, the patient must switch to a clear liquid diet, consuming only fluids like water, broth, juices, and gelatin.
The final stage involves drinking a prescribed laxative solution or taking preparation tablets, usually split into two doses. The first dose is often taken the evening before, and the second is taken several hours before the procedure. Patients are instructed to stay close to a bathroom after starting the prep, as it causes significant diarrhea, confirming the medication is working.