The walls of our stomach are completely renewed every three to four days Is that well-known fact real? Yeah, but not to the fullest extent. If you literally pour hydrochloric acid on the muscular lining of the stomach, the cells would die fairly quickly. But fortunately for us, our body has developed several defense mechanisms. And mucus, which creates a buffer between aggressive gastric juice and the wall. And also the high regenerative activity of the mucosa. Yet THE WHOLE gastric wall is not renewed in 3-4 days - it shouldn't be ALL damaged at all. Only the mucosa is in contact with the stomach's contents, and it is renewed in about this time frame.