Copyright © 1988 PMA Publishing Corp. The Eating Disorders Edited by BJ Blinder, BF Chaitin, & R Goldstein Chapter 29 Rumination: A Critical Review of Diagnosis and Treatment Barton J. Blinder, Stanley L Goodman, and Renee Goldstein INTRODUCTION umination, an uncommon disorder occurring from infancy throughout adulthood, is derived rom the Latin ruminare, "to chew the cud." Merycism, derived from the Helenic, is the act of post- ingestive regurgitation of food from the stomach back into the mouth, followed by chewing and reswallowing [1]. The two terms are often used interchangeably. Rumination is associated with medical complications such as aspiration pneumonia, electrolyte abnormali- ties, and dehydration [2] and is considered in the differ- ential diagnosis of vomiting [3] and failure to thrive [4] in infants and young children. From latency through adulthood, rumination frequently has a benign course [5]. Recently it has been associated with bulimia [6,7], anorexia nervosa, and depression [5,105,109]. Past stu- dies have ascribed the disorder to lack of emotional re- ciprocity and attunement between mother and child stemming primarily from maternal depression and anxiety [8-10]. Medical disorders such as gastroe- sophageal reflux and hiatal hernia [2,8,11,12], also are present in the population of ruminating children. Appli- cations of formal behavioral contingencies in treatment have led to describing ruminatory activity as a habit dis- order [13-15]. In DSM III [16] rumination is designated as a dis- order of infancy [307.53]. The infant shows "a charac- teristic position of straining and arching the back with sucking tongue movements and the gaining of satisfac- tion with rumination" [16]. Diagnostic criteria include repeated regurgitation without nausea or associated gastrointestinal illness for at least one month following a period of normal functioning. Weight loss or failure to make expected weight gain occur often [16]. Irritability is noted between regurgitations and hunger is often in- ferred by the observer. Although the disorder occurs most frequently after 3 months of age, it has been re- ported in a 3-week old infant [17] and in the neonatal intensive care unit [4]. Consequent failure to thrive with malnutrition may produce severe developmental delays [15]. Rumination has been described in families over four generations, and learning to ruminate by imitation has been suggested [18]. Rumination may be underreported, with only com- plicated cases (malnutrition, electrolyte disturbances, hiatal hernia) referred to a gastroenterologist and minor cases treated by parent or primary physician. Rumina- tion in anorexia nervosa and bulimia may be underre- ported due to omission of inquiry in the systematic medical history and reluctance of patients to volunteer specific clinical information [5,6,7,109]. The course of rumination may depend on the age of the patient and the severity of the complications. Mor- tality can be as high as 25% to 40% in infants [19]. Al- though the infant may manifest hyperphagia, postinges- tive regurgitation leads to progressive malnutrition (ie, a sham eating sequence). In the ruminating adolescent bulimia and affective disorder may be present [7]. Rumination in adults has been associated with gastric 315