Functional Emesis

Background: Emesis is an essential survival response, because consumption of food is a key element in the survival behavior and the act of feeding can expose the majority of internal organs to toxins, altered food, viruses, bacteria or fungi. The relationship between visceral or vestibular stimuli and the anatomical structures of the brain-gut axis explain the modulation of the gastrointestinal response. We aimed to review comprehensively the current knowledge on emesis occurring in the disorders of brain-gut interaction (DBGI), i.e. functional conditions presenting with emesis. Methods: PubMed, Cochrane Library, EMBASE and WILEY databases were screened for relevant publications from the last 20 years regarding brain-gut disorders manifesting emesis. We included in the search also idiopathic gastroparesis, as a condition paralleling the postprandial distress syndrome. Results: We critically analyzed 2 articles about chronic nausea and vomiting syndrome, 9 articles about cyclic vomiting syndrome, 9 articles about cannabinoid hyperemesis, 10 articles about idiopathic gastroparesis and 6 articles about gastroparesis like-syndrome. Contradictory results regarding the implication of environmental factors in the development of emesis in DBGI demonstrate that the underlying pathogenesis is still not completely understood.