Your Stomach Gets a New Lining Every 3 Days

The acid in your stomach has a pH between 1.5 and 3.5, strong enough to burn through metal. It needs to be that strong to kill bacteria and break down food. Your stomach protects itself with a thick layer of mucus, but that is not enough. Stem cells in your stomach wall rebuild the entire inner lining every three to four days. If this renewal stops, the acid starts to burn a hole in the stomach itself, which we call an ulcer. This fast cell division is also why stomach cancers can grow quickly.