Your not kidding!! I have been off the pred for 7wks now and the gas was horrendous!! It was to the point where I couldn't even be around anyone. It will subside when/if you taper off the med but in the meantime try Beano(over the counter)It will help. Try to not eat gassy foods too. Talk to your GI. There are antibiotics like Xifaxan that help with the excessive intestinal bacteria that causes gas. Good Luck!!
CD for 25yrs. Includes 5 bowel resections with perm. ileostomy, iron infusions, many fistulas and luckily more good days than bad.