Stomach Disease
The most common stomach diseases are ulcers, gastritis, and GERD. Ulcers are open sores that develop on the lining of the stomach or small intestine. Gastritis is inflammation of the stomach lining, and GERD is gastroesophageal reflux disease, which is a condition in which acid from the stomach backs up into the esophagus. All of these conditions can cause symptoms such as abdominal pain, nausea, vomiting, and diarrhea.