A general term for gastric ulcers (stomach) and duodenal ulcers (duodenum), open sores in the stomach or duodenum caused by digestive juices and stomach acid. Most ulcers are no larger than a pencil eraser, but they can cause tremendous discomfort and pain. They occur most frequently in the 60 to 70 age group, and slightly more often in men than in women. Doctors now know that there are two major causes of ulcers: most often patients are infected with the bacteria Helicobacter pylori (H. pylori); others are regular users of non-steroidal anti-inflammatory drugs (NSAIDS), which include common products like aspirin and ibuprofen.