Subclinical involvement of the gut in undifferentiated spondylarthropathies.

In order to evaluate the frequency of subclinical gut involvement in the seronegative spondylarthropathies, ileocolonoscopy with biopsies of the colon, ileocecal valve and ileum were performed on 211 patients with ankylosing spondylitis (AS), reactive arthritis (ReA) and undifferentiated spondylarthropathies. Inflammatory gut lesions were detected in a large number of these patients. It was concluded that the group of undifferentiated spondylarthropathies could be split into fairly equal subgroups: one subgroup suffering from subclinical inflammatory bowel disease associated with peripheral joint symptoms, a second subgroup presenting a form of enterogenic ReA, and a third subgroup in which no relation with the gut could be demonstrated. Ankylosing spondylitis, which has to be considered as a form of undifferentiated seronegative spondylarthropathy, could be subdivided into the same subgroups. These findings confirm the existence of subclinical gut involvement in patients with seronegative spondylarthropathies.