Respiratory impairment in inflammatory bowel disease: does it vary with disease activity?

Serial assessments of respiratory function were made in 44 patients with inflammatory bowel disease. Pulmonary function tests were performed at the initial assessment and after three months to see if abnormality was associated with alteration in disease activity, drug therapy or with evidence of immunological disturbance. Fourteen patients (32%) had some abnormality of respiratory function when first investigated. Seven (16%) had a reduced gas transfer factor but these abnormalities were not related to disease activity, drug therapy or any immunological variable. Elevation of both functional residual capacity and residual volume was found in nine (20%) patients at the initial assessment. These abnormalities appeared to be associated with active inflammatory bowel disease and in four of these patients lung volumes returned to normal at 3 months when the bowel disease was in remission.