My Husband Has Crohn's Disease And I Am Pretty Sure

My husband has Crohn's disease and I am pretty sure that he has ringworm on his neck and upper shoulder. My daughter nor I have it. He has been on prednisone due to a flare up, but he has had diarrhea and fowl odor from the gas (no mucus in stool) Would the ringworm assist in his digestive issues? What should he try to get rid of the ringworm?