Sacroiliitis (say-kroe-il-e-I-tis) is an inflammation of one or both of your sacroiliac joints — situated where your lower spine and pelvis connect. Sacroiliitis can cause pain in your buttocks or lower back, and can extend down one or both legs. Prolonged standing or stair climbing can worsen the pain.

Sacroiliitis can be difficult to diagnose, because it can be mistaken for other causes of low back pain. It's been linked to a group of diseases that cause inflammatory arthritis of the spine. Treatment might involve physical therapy and medications.

Dec. 18, 2015
  1. Frontera WR. Sacroiliac joint dysfunction. In: Essentials of Physical Medicine and Rehabilitation: Musculoskeletal Disorders, Pain, and Rehabilitation. 3rd ed. Philadelphia, Pa.: Saunders Elsevier; 2015. http://www.clinicalkey.com. Accessed Oct. 23, 2015.
  2. Wu DT, et al. Diagnosis and differential diagnosis of ankylosing spondylitis and non-radiographic axial spondyloarthritis in adults. http://www.uptodate.com/home. Accessed Oct. 23, 2015.
  3. Navallas M, et al. Sacroiliitis associated with axial spondyloarthritis: New concepts and latest trends. RadioGraphics. 2013;33:1.
  4. FDA Drug Safety Communication: FDA strengthens warning that non-aspirin nonsteroidal anti-inflammatory drugs (NSAIDs) can cause heart attacks or strokes. U.S. Food and Drug Administration. http://www.fda.gov/Drugs/DrugSafety/ucm451800.htm. Accessed Nov. 2, 2015.