You mentioned that your mom's bile duct is fully dilated. That would usually be a sign of a stricture, which can lead to indigestion due to a lack of bile in the bowel. You may mean something else. Anyway, if it is a stricture Creon can make sense. I do not have a stricture -- i.e., I am not dilated -- but do have biliary damage from chemo-radiation. I had terrible indigestion, gas, etc. My oncologist, Dr. Lenz at USC, has me on Creon with each meal and a daily probiotic. It has really helped!
Just my own experience, if it helps. I hope your mom feels better soon.