Role of Vagal Tone in Rumination Syndrome

Rumination syndrome is a condition in which people repeatedly and unintentionally regurgitate undigested or partially digested food from the stomach, rechew it, and then either re-swallow it or spit it out. The mechanism of the disease is not well understood. The investigators believe that discomfort in the stomach during and immediately after meals may be an important factor for this disease. The reason for such discomfort can be due to an alteration of nervous regulation of the stomach. The investigators can study the nervous regulation that affects the stomach and other parts of the body by analysing in detail an electrocardiogram that is performed continuously for several hours. From this analysis, The investigators can study a parameter called cardiac vagal tone (CVT). Diaphragmatic breathing (DiaB) is a respiratory exercise, in which people mainly move their abdomen to breath. DiaB is a common treatment for rumination syndrome. Patients doing DiaB can reduce the number of rumination episodes. The mechanism by which DiaB improves rumination is unknown. There is another type of breathing called slow deep breathing (SlowDB), in which people mainly breathe with their chest. SlowDB is used as a therapy for increased pain in the food pipe (oesophagus) and it might also be effective on rumination syndrome. The investigators believe that both DiaB and SlowDB can improve rumination, by modifying the nervous control of the stomach (that the investigators can monitor by measuring continuously cardiac vagal tone (CVT)). The aims of the study are to investigate the association between gastric discomfort during a meal, CVT variations (measured with the electrocardiogram during the meal) and the severity of rumination episodes. The investigators will also study how DiaB and SlowDB can modify this variable during the test. In a second step, The investigators will assess the clinical effect of respiratory exercises (DiaB and SlowDB) on the severity and frequency of regurgitat