The stomach is the portion of the digestive system most responsible for breaking down food. The lower esophageal sphincter at the top of the stomach regulates food passing from the esophagus into the stomach, and prevents the contents of the stomach from reentering the esophagus. The pyloric sphincter at the bottom of the stomach governs the passage of food out of the stomach into the small intestine.
Review Date 3/4/2020
Updated by: Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.