Rumination syndrome

RS is a functional gastrointestinal disorder characterized by the effortless and repetitive regurgitation of recently ingested food from the stomach to the oral cavity, followed by either re-swallowing or spitting.

The pathophysiology of RS involves a voluntary but unconscious process consisting of a coordinated abdominothoracic muscle response, including thoracic suction, crural diaphragm relaxation, and increased intragastric pressure, which collectively reverse the esophagogastric pressure gradient due to low lower esophageal sphincter and intrathoracic pressures. The exact trigger for rumination events is unclear, but they may result from dyspeptic symptoms as patients seek relief through regurgitation or venting. GERD and pathological supragastric belching can also be mechanisms provoking or aggravating RS. Enhanced visceral pain perception and poor postprandial accommodation of the stomach have been suggested as the mechanisms for epigastric pain and the feeling of bloating in patients with RS.

The prevalence of RS in the US is estimated at 5.8%, with higher rates observed in children and adolescents.

Risk factors for RS include female gender, smoking, adherence to a gluten-free diet, and allergic rhinitis. Additionally, a history of eating disorders (anorexia nervosa, bulimia nervosa) and psychiatric disorders (anxiety, depression) have been identified as independent risk factors for RS. Functional dyspepsia, gastroparesis, cyclic vomiting syndrome, and other disorders of gut-brain interaction can overlap and increase the risk of RS.

Clinically, patients with RS experience consistent postprandial regurgitation, often mislabeled as refractory gastroesophageal reflux or vomiting. Dyspeptic symptoms and minor weight loss are common. The presence of nocturnal regurgitation, dysphagia, nausea, or symptoms occurring in the absence of meals does not exclude RS, but makes the presence of it less likely.

RS is associated with depression and anxiety, and patients have a lower physical and mental QoL and increased somatic symptom reporting. The prognosis of RS is generally good with appropriate treatment. A significant reduction of 74% in rumination activity has been reported with behavioral therapy, leading to improved QoL.