A syndrome described as purging following the ingestion of normal or small amounts of food in normal-weight persons has gained increasing attention in the field of eating disorders. Various terms have been used in the literature for this newly characterized syndrome, with purging disorder and eating disorder not otherwise specified-purging (only), or EDNOS-P, used most frequently.1-8
Because purging disorder has not been included in any nosological system, there is no official definition for the disorder. As a consequence, definitions have varied across studies examining the condition, particularly with regard to the minimum required frequency of purging behaviors (ranging from once a month to twice a week for a 3-month period) and absence of objectively large binge-eating episodes (from complete absence to less than twice a week for a 3-month period).9 The Table presents criteria used in the most recent studies published by the University of Iowa Eating Behaviors Research Clinic laboratory.2,3 These criteria were modeled after those used in DSM-IV to define bulimia nervosa, which are being evaluated for possible revision in DSM-V.
Purging versus nonpurging compensatory behaviors
The definition of purging behavior has been provided in DSM-IV and includes self-induced vomiting, laxative abuse, diuretic abuse, and the use of enemas to influence weight or shape. Although some authors have examined a more broadly defined compensatory eating disorder characterized by both purging and nonpurging behaviors in the absence of binge eating, most studies have focused on a syndrome characterized by purging behaviors.10,11 Limited data have been collected to evaluate whether the distinction between purging and nonpurging (eg, fasting and excessive exercise) compensatory behaviors should be maintained either for a diagnosis of bulimia nervosa or for the formation of boundaries for purging disorder.
