Sacroiliitis and Ulcerative Colitis: What to Know

Medically Reviewed by Melinda Ratini, MS, DO on June 13, 2022
4 min read

Sacroiliitis is a type of arthritis that inflames the joints in the bottom of your spine. It can lead to pain in your lower back and buttocks. Research suggests you're more likely to get it if you have inflammatory bowel disease (IBD). Ulcerative colitis is one of two main types of IBD.

The connection between joint pain and ulcerative colitis might not seem obvious. But it's common for people with IBD to also have problems with their bones and joints. Experts think cells that trigger inflammation may travel from your intestine to your joints.

Doctors don't always catch sacroiliitis in people with IBD. So be sure to tell them if you have pain in your lower back or buttocks that won’t go away. Not treating sacroiliitis could lead to long-term back stiffness and other problems. That's on top of any diarrhea, belly pain, and other ulcerative colitis symptoms you already have.

The sacroiliac joints sit in the triangle-shaped area at the bottom of your spine (the sacrum) and connect your lower spine to your pelvis.

Ulcerative colitis causes swelling and sores in the lining of the large intestine. But it also can affect other parts of your body, like your joints, skin, lungs, or eyes.

Doctors call these extraintestinal symptoms, meaning they happen outside of your intestines. Sacroiliitis and other types of joint damage are the most common extraintestinal signs of IBD.

Injuries, arthritis, and infections are the main causes of sacroiliitis, but the condition is also more common in people with IBD. Both IBD and sacroiliitis may share some of the same genes.

You may be more likely to have sacroiliitis if ulcerative colitis affects a large part of your colon or you've lived with IBD for many years. One study found a higher rate of sacroiliitis in people who'd had IBD for more than 10 years compared to those who'd had it for 5 years or less.

Pain is the main symptom of sacroiliitis. You'll feel it in your lower back, buttock, hip, or thigh. Sometimes the pain might spread down your leg and even to your feet.

Back pain can also be a sign of an injury. The difference is that sacroiliitis pain typically lasts for more than 3 months. It's worse when you first wake up in the morning, and it improves when you move.

If you have lower back pain that's not getting better, see a rheumatologist. That’s a specialist who diagnoses and treats arthritis. The doctor will do a physical examination and press on parts of your lower back, hips, or legs to find the painful areas.

Another way to diagnose sacroiliitis is with imaging tests like X-ray, magnetic resonance imaging (MRI), or computed tomography (CT). These scans will show if you have any problems in your sacroiliac joint.

Signs of sacroiliitis could show up on an X-ray even before you have any symptoms. Or the doctor might find sacroiliitis accidentally on a CT to check your IBD.

It's important to treat sacroiliitis, especially if you're in a lot of pain. The pain can be so intense that some people can't sleep or they become depressed. In time, the bones of your spine might fuse together and make your back stiff and hard to move.

Nonsteroidal anti-inflammatory drugs (NSAIDs) can help with sacroiliitis pain and inflammation. But these pain relievers may not be a good fit for ulcerative colitis because they can trigger an IBD flare-up.

Steroids and tumor necrosis factor (TNF) inhibitors are better options. In fact, doctors prescribe TNF inhibitors to treat IBD. You get steroids as a shot into your sacroiliac joints. They relieve pain and reduce inflammation.

TNF inhibitors are given through an IV. They work by blocking a protein that causes inflammation in your intestine and joints. TNF inhibitors treat both sacroiliitis and IBD that's moderate to severe or hasn't improved with other treatments.

Examples of TNF inhibitors are:

  • Adalimumab (Humira)
  • Certolizumab (Cimzia)
  • Etanercept (Enbrel)
  • Infliximab (Remicade)

Muscle relaxants like cyclobenzaprine (Amrix, Fexmid) ease the muscle spasms sacroiliitis sometimes causes.

Radiofrequency ablation may be an option if these treatments don't work. It uses heat energy to destroy the nerves that cause pain. Surgery to fuse bones in the spine is usually a last resort if no other treatments help.

Medication isn't the only way to treat sacroiliitis. Exercise is also an important part. Moderate-intensity aerobic exercises like walking, bike riding, and swimming help to lessen pain and improve movement.

Physical therapy helps, too. A physical therapist can teach you range-of-motion exercises to stretch your sacroiliac joints and strengthen the muscles around them.

When your back hurts, try holding a cold pack or heating pad to the area. Use whichever one feels best, or go back and forth between warmth and cold.

Rest when you need to, and avoid any activities that worsen pain.