A 17-year-old boy presented for treatment with chronic diarrhea that had proven refractory to medical treatment for a period of five years. The problem was sufficiently debilitating to cause highly erratic school attendance. Anamnesis revealed no precipitating event, though it was discovered that the patient's mother was a moderately compensated, chronic schizophrenic who continued to live in the home. The patient appeared to be the focus of family conflicts generated by her condition, and his individuation efforts were thwarted by her needs for constant care and support. The patient's diarrhea was understood from two perspectives. On an intrapsychic level, it was a manifestation of suppressed rage towards the mother for the sacrifice of his automony. On a family systems level, it served the function of keeping the patient in the home, and seemed part of a family collusion demanding that someone be available to monitor and care for the mother. A treatment approach was developed, consisting of individual therapy designed to facilitate the ventilation of the patient's anger, and family sessions in order to clarify the nature and limits of his responsibilities to the mother. After several visits, the patient's diarrhea was in complete remission. (Author)