I may be wrong but I think another possible reason you're not supposed to take Immodium with Crohn's is because a lot of people with Crohn's have like narrowing or strictures and they don't want to cause a blockage.
That being said, I couldn't live without Immodium and I totally still take it all the time. You do what you have to, to get through the day.
28 Year old Female
Diagnosed with Crohn's Colitis March 2000
Recent possible diagnosis of IBS-D
Tried Meds: Asacol, Remicade, 6mp, Humira, Xifaxan, Apriso, Rowasa Enemas.
Currently on: 25mg Prednisone (Tapering SLOWLY from 60), 100mg Imuran, Psyllium Seed Powder, Prenatal Vitamin, Vitamin B 12 Complex, Vitamin D/Calcium, Flomax (for urinary retention).