Idiopathic inflammatory bowel diseases often coincide with seronegative spondyloarthropathies and rheumatoid arthritis. During ankylosing spondylitis 30-60% of patients tend to have minimal changes of idiopathic inflammatory bowel diseases in the large bowel. Aetiology of the mentioned diseases is not clearly understood yet, but the genetic background is common (existence of HLA-B27 antigen in seronegative spondyloarthropathies, idiopathic inflammatory bowel diseases and MHC class II DRB1 in rheumatoid arthritis and idiopathic inflammatory bowel diseases) as well as immunological disturbances – hyperactivation of T CD4+ lymphocytes, excessive generation of inflammatory cytokines (IL-1, TNF-α). This publication covers the case of coincidence of rheumatoid arthritis and ankylosing spondylitis accompanied by ulcerative colitis.