Chronic ruminative vomiting: a comparison of four treatment procedures.

An experimental analysis of a case of chronic ruminative vomiting in a 15-year-old, profoundly retarded, Down's syndrome boy addressed the consequences of vomiting in the postmealtime environment. The experiment compared four treatments in each hour-long session using a multiple reinforcement schedule with order of the following procedures counterbalanced over days in a Latin square design: differential reinforcement of any behaviors other than vomiting (DRO) in which periods of no vomiting were followed by reinforcement and vomiting postponed reinforcement; differential reinforcement of specific behaviors alternative to vomiting (DRI) in which conjoint periods of no vomiting and sustained toy play were followed by reinforcement and the lack of either postponed reinforcement; extinction plus reinforcement of alternative behavior in which vomiting was ignored but toy play was reinforced; extinction in which vomiting was ignored. Data revealed an orderly dual cyclical pattern of vomiting throughout the day, with increased vomiting in the morning and immediately following food ingestion. Postluncheon treatments emphasizing reinforcement of alternative behavior were more successful in decreasing vomiting than DRO or extinction alone.