The stomach is a muscular organ located on the left side of the upper abdomen that receives food from the esophagus. As food reaches the end of the esophagus, it enters the stomach through a muscular valve called the lower esophageal sphincter.
Dyspepsia means stomach indigestion or an upset stomach.
Gastritis is the inflammation of the stomach usually by alcohol, medications, H. pylori infection or other factors.
Gastroesophageal reflux (GERD)
When stomach contents and acid travel backward up the esophagus. The most common symptom is heartburn.
Stomach bleeding is when you see black or blood material in your stool. Typically gastritis, ulcers and gastric cancers cause bleeding.