Perianal fistulizing Crohn’s disease (PCD) is a complication of Crohn’s that affects up to 40% of Crohn’s patients. Fistulas form when abnormal connections form between the intestine and surrounding tissue.  Specifically, in the presence of inflammation, ulcers extend through the entire intestinal wall, creating a tunnel that drains pus away from the inflamed area. Fistulas may occur anywhere along the GI tract and are very painful and difficult to treat.

In good news for patients, a 2025 study published in The Journal of Clinical Investigation identifies new factors that contribute to fistulas. Examining samples of patients with PCD, researchers found that a specific immune signal--interferon gamma (IFN-γ)—was highly active in patients with PCD. This over-activation was linked to inflammation and changes in tissue that allow fistulas to form and persist.

The study also identified high numbers of a type of white blood cell, Th17 immune cells, which help protect the body from infections. In PCD, however, these cells produced large amounts of IFN-γ, fueling inflammation and tissue damage. Together with other immune cells, they created a cycle that drives fistula formation.  Combined, these new findings may pave the way for more effective treatments of fistulas and much needed relief for patients.

References

​Crohn’s & Colitis Foundation

Revealing hyperactivated IFN-γ pathways in perianal fistulizing Crohn’s disease using single-cell and spatial multi-omics, J Clin Invest. 2025; 135(17):e193413.

Service dogs are specially trained to help people with disabilities, including people with Crohn's disease.  Under the Americans with Disabilities Act (ADA) service dogs are allowed in public places like restaurants, schools, stores, and airplanes. Service dogs offer emotional support and can help with important tasks that are challenging during episodes of pain or fatigue.  Typical daily tasks that a service dog can be trained to help with  are:

• Carrying heavy items like backpacks or books
• Opening doors
• Switching lights on and off
• Fetching items such as a cellphone 
• Reminding to take a medication

Some patients report that their dogs also can recognize symptoms of a flare, sometimes before their owner does.  Another important benefit of service dogs is that they encourage their owners to be more active. Like all dogs, service dogs need exercise and playing with their owner outdoors is a great way to get it.

Determining whether a service animal is right for your child also requires careful consideration of whether your family is ready to take on the costs, new routines, veterinary care, and special training required to integrate a dog successfully into your home. 

To find out if a service dog might be right for your family, talk to your doctor and consult an accredited member of  Assistance Dogs International.