I have CD and am taking both Donnatal and Lomotil. I'm also taking DTO (distilled tincture of opium). The DTO and Lomotil were prescribed to help slow things down. I have an ileostomy and have short bowel syndrome, so almost anything I eat goes right through me. The thinking is that if we slow things down I might be able to retain some of the nutrients. The drugs do help. The Donnatal was prescribed more recently to help reduce the pain; it is an antispasmodic.
I don't agree that these drugs are more for IBS than Crohns, but I'm not a professional. What doses are you taking? I take 2 tsp. of Donnatol as needed for pain. I take 2 Lomotil tablets four times a day, and the DTO is 30 drops 4 times a day.
Have you tried any of the other CD drugs like Imuran, Humira or Remicade?