Objective. To search for an association between gut infection, gut inflammation, and spondylarthropathies.

Methods. Ileocolonoscopy was performed in 118 patients with various inflammatory and noninflammatory joint diseases and in 24 patients with uncomplicated acute bacterial gastroenteritis.

Results. Endoscopic lesions were more frequent in patients with spondylarthropathy (44%) compared with those with other inflammatory arthritides (6%; P = 0.001). Ileal changes were observed only in patients with spondylarthropathy (20% versus 0%; P = 0.01). Inflammatory bowel disease was the endoscopic diagnosis in 19% of the arthritis patients. Possible or definite Crohn's disease was diagnosed in 26% of patients with chronic spondylarthropathy, and ulcerative colitis in 1 patient with rheumatoid arthritis and in 1 with chronic uroarthritis. Histologic evidence of inflammation differed less distinctly than endoscopy findings between patient groups. There was no association of gut lesions with the use of nonsteroidal antiinflammatory drugs or with the presence of HLA-B27.

Conclusion. Gut inflammation is frequent in patients with spondylarthropathy, and one-fourth of the patients who have chronic disease have early features of Crohn's disease.