Overview
Rumination syndrome is a condition in which people repeatedly and unintentionally spit up (regurgitate) undigested or partially digested food from the stomach, rechew it, and then either reswallow the food or spit it out. The food hasn't been digested, so people with rumination syndrome often report that the food tastes normal, not acidic like vomit. Rumination typically occurs every day, and at every meal, usually within 30 minutes of eating.
The precise cause of rumination syndrome is unknown, but it's clear that rumination is a subconscious behavior, not a conscious decision. Rumination syndrome is frequently confused with bulimia nervosa, gastroesophageal reflux disease (GERD) and gastroparesis. Some people have rumination syndrome and constipation caused by a rectal evacuation disorder.
The condition has long been known to occur in infants and people with developmental disabilities, which may be related to an unvoiced desire to reject food. But it can also occur in other children, adolescents and adults. It's not clear how many people have this disorder.