Endoscopy and colonoscopy are minimally invasive procedures used to examine the digestive tract, which runs from the mouth to the rectum. These diagnostic tools use a long, flexible tube equipped with a camera and light source for real-time visual inspection. Upper gastrointestinal (GI) endoscopy examines the esophagus, stomach, and the first part of the small intestine (duodenum). Colonoscopy focuses specifically on the large intestine (colon) and the rectum. Both procedures identify abnormalities, such as inflammation, ulcers, or growths, and allow for the collection of tissue samples (biopsies) for definitive diagnosis.
Diagnoses via Upper Gastrointestinal Endoscopy
Upper GI endoscopy (EGD) diagnoses conditions affecting the upper digestive system. A common finding is damage related to Gastroesophageal Reflux Disease (GERD), where stomach acid flows backward into the esophagus. This acid exposure causes esophagitis (inflammation of the esophageal lining) and can lead to Barrett’s Esophagus. Barrett’s Esophagus involves a change in the tissue lining the lower esophagus, which carries a risk of developing into esophageal cancer.
The procedure identifies peptic ulcers, which are open sores on the lining of the stomach (gastric ulcers) or the duodenum (duodenal ulcers). Endoscopy also determines the source of unexplained upper GI bleeding, which may stem from ulcers, tears in the esophageal lining, or enlarged veins called esophageal varices, often associated with liver disease. Visual inspection can also reveal inflammation in the stomach (gastritis) and duodenum (duodenitis).
Endoscopy is used to diagnose Celiac Disease, an autoimmune disorder triggered by gluten consumption. The physician looks for characteristic flattening of the villi lining the small intestine and takes biopsies to confirm the damage. The procedure also allows for the detection of non-cancerous and cancerous tumors in the esophagus and stomach, enabling early intervention.
Diagnoses via Colonoscopy
Colonoscopy provides a detailed view of the large intestine and rectum, making it the preferred method for detecting diseases in the lower GI tract. A primary focus is the detection and removal of colorectal polyps, which are growths on the lining of the colon. While often benign, certain types of polyps, such as adenomas, are considered pre-cancerous and can develop into colorectal cancer.
The ability to remove these polyps during the procedure (polypectomy) is a major factor in preventing colorectal cancer. Colonoscopy is also used to diagnose colorectal cancer directly, allowing visualization of cancerous tissues and collection of biopsies to confirm malignancy. The procedure plays a significant role in diagnosing Inflammatory Bowel Disease (IBD), which includes Crohn’s Disease and Ulcerative Colitis.
In Ulcerative Colitis, inflammation is generally limited to the colon and rectum. Crohn’s Disease, however, can cause inflammation anywhere in the digestive tract, frequently involving the colon. Colonoscopy allows the physician to observe the specific patterns of inflammation and tissue damage characteristic of each condition. Other diagnoses include diverticulosis (small pouches forming in the colon wall) and diverticulitis (when these pouches become inflamed or infected). Colonoscopy also investigates the source of lower GI bleeding, which may be caused by hemorrhoids, polyps, or active inflammation.
Using These Procedures for Screening and Follow-up
Both upper endoscopy and colonoscopy are utilized for proactive screening and long-term disease monitoring, not just acute diagnosis. Screening involves performing the procedure on individuals without symptoms to detect disease at its earliest, most treatable stage. For example, colorectal cancer screening guidelines recommend that individuals at average risk begin routine colonoscopies at age 45, since precancerous polyps often produce no symptoms.
Upper endoscopy screens for complications in high-risk groups, such as those with chronic, severe GERD who are monitored for Barrett’s Esophagus. Once a diagnosis is established, these procedures monitor the progression or recurrence of chronic conditions. Individuals with IBD, for instance, undergo repeat colonoscopies to assess disease activity, check treatment effectiveness, and screen for cancer risk.
Patients who have had pre-cancerous polyps removed are placed on a surveillance schedule, requiring follow-up procedures to ensure no new polyps have formed. Similarly, those diagnosed with Barrett’s Esophagus require periodic upper endoscopies with biopsies to monitor the tissue for signs of advancing cell changes.