A 66-year-old man developed chronic watery diarrhea and progressive dyspnea over 1-year. Colonic biopsy revealed a thickened subepithelial collagen layer consistent with collagenous colitis; open lung biopsy revealed pulmonary fibrosis. Only one previous report links extraintestinal manifestations to collagenous colitis. Although the patient had been taking sulfasalazine, the case supports the idea that collagenous colitis, like inflammatory bowel disease, is part of a systemic disorder.