Lymphocytic colitis is a rare inflammatory colonic disease of unknown etiology accompanied by watery diarrhea. Diagnosis is based upon pathological examination of colonic biopsies. Treatment essentially involves antiinflammatory agents such as sulfasalazine/5-ASA or corticosteroids if necessary. We report the case of a female patient suffering from severe lymphocytic colitis who remained unresponsive after 5-ASA therapy but who improved dramatically after oral budesonide administration.