A clinical case is presented in which ulcerative colitis appeared as an acting out of a homosexual fantasy. The patient had a defective and sadistic superego, the ego adopting a masochistic position in order to accept the double aspect of the impaired superego. This patient had the need to 'control' the mother or mother surrogates through colonic activity. Ramifications of the unconscious fantasies were obtained primarily through the acting out in the transference as well as through the author's countertransference fantasies. There was a secondary gain in that the patient succeeded in splitting the partners in the Oedipal situation.