A stomach ulcer, also known as a peptic ulcer, is a painful sore that develops on the lining of the stomach or the first part of the small intestine, called the duodenum. This damage occurs when the protective mucus layer of the digestive tract is worn away, allowing stomach acid to erode the underlying tissue. The most common symptom is a burning or gnawing pain in the upper abdomen, often occurring between meals or at night. Other signs may include nausea, bloating, and unexplained weight loss. Because these symptoms overlap with many other digestive issues, medical testing is required to confirm the presence of an ulcer, determine its cause, and ensure the condition is properly treated.
Identifying the Bacterial Cause: H. Pylori Tests
The primary cause of peptic ulcers is often an infection by the bacterium Helicobacter pylori (H. pylori). Detecting the presence of this bacterium is a crucial step in the diagnostic process, as its identification dictates the course of treatment, which typically involves antibiotics. Doctors use several non-invasive methods to check for an active H. pylori infection, mainly focusing on the unique biological activity of the organism.
One common method is the Urea Breath Test (UBT), which relies on the fact that H. pylori produces an enzyme called urease. This enzyme breaks down urea into ammonia and carbon dioxide. For the test, a patient swallows a solution containing a small amount of labeled urea. If the bacteria are present, the labeled carbon dioxide gas is produced and absorbed into the bloodstream, eventually being exhaled in the breath. Preparation for this test typically requires fasting for several hours and temporarily stopping certain medications like proton pump inhibitors for up to two weeks, as these can lead to a false-negative result.
Another highly accurate, non-invasive option is the Stool Antigen Test (SAT). This test directly looks for specific proteins, or antigens, related to the H. pylori bacteria within a collected stool sample. Since the test detects the actual bacterial markers, a positive result confirms an active infection. The SAT is also frequently used to confirm that the infection has been successfully eradicated after a patient completes antibiotic treatment.
A third method involves a simple Blood Test, which measures antibodies the immune system produces in response to H. pylori. Unlike the breath and stool tests, a positive blood test cannot distinguish between a current active infection and one that the body successfully fought off years ago. Because the antibodies can remain in the blood long after the bacteria are gone, this test is generally used less often for diagnosing an active ulcer and more for initial screening in certain populations.
Direct Visual Confirmation: Upper Endoscopy
The most definitive way to diagnose a stomach ulcer is through an Upper Endoscopy, also known as Esophagogastroduodenoscopy (EGD). This procedure allows a specialist to visually inspect the lining of the upper digestive tract, including the esophagus, stomach, and duodenum. The patient is typically given a sedative before an endoscope is gently guided down the throat.
The direct visualization provided by the endoscope confirms the presence of an ulcer, revealing its exact size, number, and location within the stomach or duodenum. Endoscopy also provides the opportunity for immediate therapeutic action, such as controlling any active bleeding from the ulcer. Fasting for several hours before the procedure is necessary to ensure the stomach is empty, allowing for a clear view of the lining.
A critical advantage of the EGD is the ability to take small tissue samples, a process called a biopsy, during the procedure. Tiny tools passed through the endoscope can obtain samples from the edges and base of the ulcer. These samples are then examined in a laboratory to check for the presence of H. pylori directly within the stomach lining, which is the most accurate way to detect the bacteria.
Biopsies are also performed to rule out malignancy, as some gastric ulcers can be cancerous. This step is particularly important for ulcers located in the stomach, as duodenal ulcers are rarely malignant. If a gastric ulcer is found, multiple tissue samples are taken from various points to ensure any abnormal cells are detected and to stage the severity of any underlying gastritis.
Alternative Imaging Techniques
An imaging test called an Upper GI Series, or Barium Swallow, may be used when endoscopy is not feasible. This non-invasive test uses X-rays to visualize the internal structure of the upper digestive organs. The patient drinks a thick, chalky liquid containing barium sulfate, which temporarily coats the lining of the esophagus, stomach, and duodenum.
Barium outlines the contours of the organs on the X-ray images. An ulcer will show up as a crater or a collection of barium that interrupts the smooth line of the digestive tract wall. This technique can successfully identify the presence of a larger ulcer.
However, the Upper GI Series is less sensitive than endoscopy for detecting smaller ulcers and cannot determine the cause of the ulcer. This X-ray method does not allow the doctor to take a biopsy to check for H. pylori or to rule out the possibility of cancer.