A functional analysis was conducted to identify the role environmental variables had on the maintenance of self-injury and aggression. At the outset of the evaluation, an abdominal x-ray showed a moderate to large amount of stool throughout the colon (i.e., constipation). Consequently, medication was administered to promote bowel emptying. Initial high rates of self-injury and aggression reduced to near-zero levels following bowel cleanout, yielding undifferentiated functional analysis results. (Contains 6 figures and 2 notes.)