Stomach polyps are rare, occurring in about 1 % of people undergoing upper gastrointestinal endoscopy — a procedure that examines the lining of the stomach.
The three most common types of stomach polyps are:
- Hyperplastic polyps. These stomach polyps account for more than half of all diagnosed stomach polyps and develop into cancer in about 2 percent of cases.
- Fundic gland polyps. These stomach polyps, found in the top portion of the stomach (fundus), don’t become cancerous, except in people with familial adenomatous polyposis (FAP) syndrome.
- Adenomas. Adenomas have a significant chance of becoming cancerous and arise from the stomach’s glandular tissue, accounting for about 10 % of stomach polyps.
Doctors Aren’t sure why fundic gland stomach polyps develop. However, several problems can cause the gastritis that contributes to hyperplastic polyps and adenomas.
The most common cause of chronic gastritis is infection by Helicobacter pylori (H. pylori) bacteria, which can also cause ulcers. About 20 percent of American adults under age 40, and 50 percent of those over age 60 carry these bacteria in their stomachs. Although H. pylori doesn’t always cause problems, it can infect and inflame the stomach lining. The resulting damage can set the stage for polyps. One study found H. pylori in 40 percent of people diagnosed with hyperplastic gastric polyps.
Another cause of chronic gastritis is an autoimmune reaction, in which your body forms antibodies that attack cells in the stomach and a protein needed for absorbing vitamin B-12. This process may cause vitamin B-12 deficiency anemia in many people with stomach polyps. Anemia is a condition in which you don’t have enough healthy red blood cells to carry adequate oxygen to tissues.
Factors that increase your chances of developing stomach polyps are:
- Age. Most people with hyperplastic polyps and adenomas are in their 60s or older.
- H. pylori infection. This is a common cause of the gastritis that contributes to hyperplastic polyps and adenomas. Experts aren’t sure how people become infected with these bacteria, but H. pylori may be carried in food and water. H. pylori infection is more common in older adults.
- Familial adenomatous polyposis. This condition is hereditary and is caused by genetic mutations that occur in one in 7,000 to 22,000 people.
- Medication use. Long-term use of proton pump inhibitors (PPIs) such as omeprazole (Prilosec) — which are used to treat ulcers, gastroesophageal reflux disease (GERD) and H. pylori infection — has been linked to fundic gland polyps. However, it’s not clear whether these medications actually cause polyp growth or whether polyp growth is due to the presence of H. pylori.
Small polyps usually don’t cause symptoms. However, as a stomach polyp enlarges, ulcers may develop on its surface, or rarely, the polyp may block the opening between your stomach and your small intestine.
If you have stomach polyps, you may experience:
- Abdominal pain, or tenderness when you press your abdomen
- Nausea and vomiting
- A sense of fullness too soon while you’re eating
Signs and symptoms of inflammation of the stomach (gastritis), which may lead to hyperplastic polyps and adenomas, also include abdominal pain, as well as belching, bloating, nausea and bleeding signaled by blood in the vomit or black stools. People with familial adenomatous polyposis (FAP), which is associated with fundic gland polyps, may also develop hundreds of colorectal polyps at a young age. Signs and symptoms of colorectal polyps include bleeding and fatigue.
If you have stomach polyps, odds are good that your doctor detected them while looking inside your stomach because of other problems — not necessarily polyps — that may have been causing symptoms. Imaging procedures — such as X-ray and computerized tomography (CT) scan — may be used to diagnose polyps, but they’re usually found incidentally when these tests are done for another reason. More commonly, polyps are found by an upper gastrointestinal endoscopy.
An upper gastrointestinal endoscopy is a procedure in which a flexible, lighted tube is used to allow your doctor to view your esophagus, stomach and the first part of your small intestine. The device also inflates your stomach with air, allowing the doctor to look at the stomach’s folds. This procedure can reveal growths, red spots, bleeding and inflammation in the stomach.
If polyps are found during an endoscopy, your doctor may take tissue samples (biopsy) or remove the entire growth using special tools inserted through the endoscope. These include a small cutting device or a wire loop that burns tissue then snares it. A doctor can determine which type of polyp you have by examining its cells under a microscope.
Depending on the type of polyp you have, your doctor may recommend a follow-up endoscopy in a year or two to see if more polyps have developed.
When a stomach polyp is seen during endoscopy, a biopsy is usually taken. If there’s concern that it may develop into cancer, it’s removed. Surgical removal is done either by the gastroenterologist during another upper endoscopy or, if that can’t be done, then by a surgeon through an incision through your abdomen.
If you have gastritis caused by H. pylori bacteria in your stomach, eradicating the bacteria with antibiotics can reduce the likelihood that your polyps will return. Your doctor can determine whether you have H. pylori through a blood test. Another test requires you to drink a special liquid. Then, a machine analyzes your breath for signs that the bacteria are present in your stomach.
Your doctor may prescribe antibiotics — probably more than one type — for you to take for several weeks to kill the H. pylori bacteria.