A gastroenterologist is a medical specialist focused on the entire digestive system, including the gastrointestinal tract and accessory organs like the liver, pancreas, and gallbladder. They address the function and health of all organs involved in digestion and nutrient absorption, from the esophagus to the rectum. Gastroenterologists employ a wide array of procedures for both diagnosis and treatment of conditions such as inflammatory bowel disease, acid reflux, and liver disorders, often managing complex issues without the need for traditional surgery.
Procedures for Direct Visualization and Screening
Many common gastroenterology procedures utilize endoscopy, which involves inserting a flexible tube equipped with a camera and light source into the body to visualize the digestive lining. This direct visualization is foundational for diagnosing many conditions and is routinely used for preventive screening. The procedures are minimally invasive and allow physicians to identify abnormalities, such as inflammation, ulcers, and tumors, that might otherwise be missed by imaging alone.
Upper endoscopy, or Esophagogastroduodenoscopy (EGD), examines the upper GI tract. The endoscope is guided through the mouth, past the esophagus and stomach, and into the duodenum. EGD is often used to investigate symptoms like persistent heartburn, difficulty swallowing, or upper abdominal pain. During the procedure, the gastroenterologist can pass tiny instruments through the endoscope to take tissue samples (biopsies) or to treat bleeding.
Colonoscopy examines the large intestine and rectum by inserting a colonoscope through the anus to view the entire colon. It is a standard tool for colorectal cancer screening, allowing for the detection and removal of precancerous growths called polyps. This removal process, called polypectomy, prevents polyps from developing into cancer.
Flexible sigmoidoscopy visualizes only the rectum and the lower part of the colon (sigmoid colon). Because it does not examine the entire large intestine, it requires less extensive preparation than a full colonoscopy. This procedure is used to investigate bleeding or other symptoms focused in the lower bowel or as a quick screening option that does not require sedation. The sigmoidoscope allows for tissue sampling and the removal of localized polyps.
Specialized Therapeutic and Interventional Procedures
Gastroenterologists perform advanced procedures that combine endoscopy with therapeutic intervention. Endoscopic Retrograde Cholangiopancreatography (ERCP) is used to find and treat problems within the bile ducts and pancreatic duct. The procedure involves passing an endoscope to the small intestine, injecting a contrast dye, and making the ducts visible on X-ray imaging. ERCP is primarily therapeutic, allowing the physician to remove gallstones or place small tubes, called stents, to relieve blockages caused by tumors or scar tissue.
Endoscopic Ultrasound (EUS) integrates an ultrasound device onto the tip of a standard endoscope. This allows the physician to produce images of the digestive tract wall and surrounding organs like the pancreas and lymph nodes. EUS is useful for accurately staging cancers by determining the depth of tumor invasion and whether the cancer has spread to nearby lymph nodes. The device also allows for EUS-guided fine needle aspiration (FNA) to obtain tissue samples from suspicious masses or cysts outside the digestive tube for diagnosis.
Gastroenterologists employ techniques to treat early-stage digestive cancers without major surgery. Endoscopic Mucosal Resection (EMR) is used to remove superficial, non-invasive tumors or large polyps from the lining of the esophagus, stomach, or colon. Radiofrequency Ablation (RFA) delivers heat energy through an endoscope to destroy abnormal tissue, often used to eliminate precancerous cells in the esophagus associated with Barrett’s esophagus. These interventional procedures offer less invasive alternatives for patients with localized disease.
Functional and Motility Assessments
Some digestive problems are caused by issues with the muscles and nerves that control movement and pressure within the tract, rather than structural abnormalities. Esophageal manometry evaluates the function and strength of the muscles in the esophagus. A thin, pressure-sensitive catheter is passed through the nose into the esophagus to measure the force and coordination of muscle contractions when the patient swallows water. This test is used to diagnose motility disorders like achalasia or to evaluate patients experiencing difficulty swallowing or chest pain.
pH monitoring assesses the amount and nature of reflux from the stomach into the esophagus over a 24 to 48-hour period. A small probe is placed in the esophagus to measure acid (pH) and non-acid fluid movement (impedance). This test is often performed after manometry determines the correct placement of the sensor and confirms a diagnosis of Gastroesophageal Reflux Disease (GERD). The patient wears a small recorder and keeps a diary of symptoms, correlating reflux episodes with their daily activities.
Anorectal manometry measures the pressures and coordination of the anal and rectal muscles. A catheter with pressure sensors is inserted into the rectum to evaluate the strength of the anal sphincter muscles and rectal sensation. This assessment is performed without anesthesia and helps diagnose the causes of chronic constipation or fecal incontinence. The test often includes a balloon expulsion test to evaluate the patient’s ability to coordinate the muscles necessary for a bowel movement.
Non-Endoscopic Diagnostic Techniques
Gastroenterologists rely on several diagnostic tools that do not involve endoscopy. Capsule endoscopy is a non-invasive procedure where the patient swallows a vitamin-sized capsule containing a camera. This camera takes thousands of images as it travels through the digestive tract, transmitting them to a recorder worn on the patient’s waist. The primary utility of this procedure is visualizing the entire small intestine, an area largely inaccessible to standard endoscopes.
Capsule Endoscopy Review
The images captured by the camera pill are compiled into a video for the physician to review, helping to identify sources of obscure bleeding or diagnose conditions like Crohn’s disease. The capsule is diagnostic only, meaning it cannot perform biopsies or therapeutic interventions, and it is passed naturally during a bowel movement.
Liver Biopsy
Liver biopsy is an important diagnostic procedure involving inserting a needle through the skin to obtain a sample of liver tissue. Although sometimes performed by a radiologist, the gastroenterologist typically orders the test and interprets the results. This procedure diagnoses the severity of liver diseases, such as hepatitis or cirrhosis.
Breath tests are used to diagnose common gastrointestinal infections and intolerances. The urea breath test detects the presence of Helicobacter pylori, a bacterium associated with ulcers and gastritis. The test involves drinking a special solution, after which the patient breathes into a bag, and the sample is analyzed for bacterial byproducts. Other breath tests measure hydrogen and methane gases after consuming a sugar solution, diagnosing Small Intestinal Bacterial Overgrowth (SIBO) or lactose intolerance.