Inflammatory disease of the bowel- regional enteritis (Crohn's disease) and ulcerative colitis- are often associated with arthritis. This occurs because inflammation in the bowel and the joints may share a common immunological abnormality.

Patients can present with abdominal pain, weight loss, and diarrhea.

Clinically, the arthritis that accompanies inflammatory bowel disease occurs in two different ways. The first pattern typically affects the larger joints of the lower extremities such as the ankles and knees. The heels may also be affected. Sometimes the fingers or toes can swell and look like little sausages. This type of ?peripheral? arthritis occurs in about 20 per cent of patients who have inflammatory bowel disease. The activity of the arthritis parallels the gut activity.

In the second type, the arthritis can affect the low back- the sacroiliac joints that join the pelvis to the lower spine. This type of arthritis occurs in about 15-20 per cent of inflammatory bowel patients. A genetic marker called HLA-B27 is present (found through a blood test) in 50 per cent of patients who have inflammation of the sacroiliac joints. Stiffness in the low back along with limited range of motion is seen. This type of arthritis does not parallel the gut activity.

The diagnosis is usually suspected from the presence of bowel symptoms such as diarrhea and abdominal cramping. Rarely, the arthritis may precede the bowel symptoms.

The diagnosis is confirmed by laboratory testing, x-rays, bowel visualization (colonoscopy), and magnetic resonance imaging (MRI).

The treatment for the arthritis associated with inflammatory bowel disease is remarkably similar to that involving other types of arthritis. Typically anti-inflammatory drugs and disease-modifying drugs are both used. Anti-inflammatory drugs should be used with caution since they may cause the bowel disease to flare up. More recently, biologic drugs have been used with success to treat inflammatory bowel disease. The arthritis not surprisingly, also responds.