In the present report the authors describe four cases with megacolon and arthritis. The etiology of these unique associations is known in only one case. The musculoskeletal pictures belong to the group of seronegative spondyloarthritis. A huge resistance with great scibalas was detected in the left iliac region by physical examination in all cases. Surgical procedures of the colon resulted in complete remission of arthritis in one case, in the others, chronic obstipation with intermittent relapse of arthritis persisted.