Biologic Aspects of Rumination Syndrome, Eosinophils, and Beyond

Abstract

Rumination syndrome is characterized by repeated regurgitation with re-swallowing or spitting. It is associated with both medical and psychosocial complications. It is a disorder of gut-brain interaction resulting from complex and heterogenous interactions across biologic, psychologic, and social systems. Diaphragmatic breathing to compete with abdominal wall contractions is the current mainstay of treatment but is often only associated with partial improvement and high relapse rates. As such, there is a need to develop other treatments to supplement the current behavioral approach, particularly addressing other targets of therapy as defined within the biopsychosocial model. The purpose of this chapter is to describe current knowledge of the biology of rumination syndrome, suggesting other potential therapeutic targets including both mechanical and immune dysfunction. Frequent coexistence of GERD and functional dyspepsia has been demonstrated in both adults and children with rumination syndrome, and both may be triggers for rumination. Thus, the biology of both is relevant to rumination, and, as such, the biologic mechanisms of both may represent viable treatment targets in rumination syndrome. Immune dysfunction is now highly implicated in other disorders of gut-brain interaction with emerging data implicating a role in rumination syndrome independent of the presence of functional dyspepsia.