Ankylosing spondylitis is not simply a back problem. It is a systemic inflammatory condition that targets the spine, sacroiliac joints, and in a significant number of cases, the gut, eyes, and peripheral joints.

If you live with inflammatory bowel disease — whether Crohn's disease or ulcerative colitis — and you also deal with joint pain, stiffness, or swelling, you are not imagining a connection. IBD-associated arthropathy is one of the most common extraintestinal manifestations of IBD, affecting anywhere from 17 to 39 percent of patients depending on the classification used.

Post-streptococcal reactive arthritis catches most people completely off guard. You had a strep throat — you took the antibiotics, you felt better — and then weeks later your joints started swelling. The infection was treated, the bacteria were gone, and yet here you are with arthritis that no one seems to have a clear answer for.