A colonoscopy is a diagnostic and screening procedure used to examine the lining of the large intestine (colon and rectum). Its main purpose is to screen for colorectal cancer by identifying and removing precancerous growths called polyps, and to diagnose various digestive issues. Because the procedure requires advanced technical skill and specialized medical knowledge, it is performed by several types of highly trained physicians.
Gastroenterologists The Primary Experts
Gastroenterologists specialize in the digestive system, including the esophagus, stomach, small intestine, and colon. Their training involves a three-year internal medicine residency followed by a three-year fellowship focused on gastrointestinal diseases and endoscopic procedures. This focused training makes them the specialists who perform the vast majority of colonoscopies, particularly for routine screening.
During their fellowship, they receive extensive hands-on experience in diagnostic and therapeutic endoscopy, including removing polyps and managing complications. They are experts in interpreting visual findings, ensuring a thorough examination of the entire colon, and determining the appropriate surveillance schedule. Trainees typically need to perform an average of 275 colonoscopies to achieve proficiency in the complex motor and cognitive skills involved.
Surgical Specialists Who Perform Colonoscopy
Surgical specialists also regularly perform colonoscopies. General surgeons are trained in a wide range of surgical procedures and may include colonoscopy as part of their practice, often exhibiting comparable complication and completion rates to gastroenterology colleagues.
Colorectal surgeons (sometimes called proctologists) are general surgeons who complete an additional one to two-year fellowship focused on the surgical treatment of the colon, rectum, and anus. These specialists often perform colonoscopies for patients with complex anatomical challenges, a history of prior colorectal surgery, or when a high risk of surgical intervention is anticipated. This expertise is beneficial when a diagnostic procedure may quickly transition into an advanced therapeutic or surgical intervention, such as the removal of a large, complex polyp.
Training and Credentials for Quality Care
The quality of a colonoscopy depends less on the specific specialty and more on the physician’s training, experience, and adherence to quality metrics. One important measure is the Adenoma Detection Rate (ADR), which is the percentage of screening colonoscopies where the physician finds and removes at least one precancerous polyp. A higher ADR is directly linked to a lower risk of developing colorectal cancer following the procedure.
Current quality benchmarks require a minimum ADR of 25% for a mixed-gender population (30% for men and 20% for women). Other quality indicators include the cecal intubation rate, which should be 95% or higher for screening exams, and the withdrawal time, which should be at least six minutes spent looking for polyps as the scope is pulled out.
Patients should choose a physician who is Board Certified in their field, such as by the American Board of Internal Medicine (Gastroenterology) or the American Board of Colon and Rectal Surgery. Board certification signifies that the doctor has met rigorous national standards for education, knowledge, and clinical skills, and participates in ongoing continuing education. Patients are encouraged to ask their provider about their personal quality metrics, such as their ADR, to make an informed decision.