Gravity

When someone lies down with a full stomach, gravity pushes stomach contents against the lower esophageal sphincter. Mechanical stress from repeated nightly pressure accumulates over time and reduces sphincter function. Gravity contributes to reflux risk by pushing full-stomach contents against the sphincter when a person lies down. Gravity on a full stomach is presented as one of the combined causes of cardiac sphincter opening and reflux symptoms. The sphincter struggles to maintain integrity under repeated pressure from a full stomach in a horizontal position. Gravity's downward pressure contributes to conditions that favor acid reflux when combined with stomach distension and stress-related sphincter opening.