Ibuprofen is not good, even by itself, for Crohn's. Perhaps somebody else will be able to answer your question about other pain meds.
Exercising might help prevent cramps.
Daughter (22) Dx'd Crohn's 3/06. Misdiagnosed for two years, including by top pediatric Crohn's specialist as stress. No symptoms for the past three years. March '09 colonoscopy showed stricture gone but two spots of inflammation in TI. Used LDN to taper off Entocort last fall. (Was on Entocort since April 06.) Never had D. 4.5 mg LDN, SCD multivit, homemade yogurt, 2000IU vit D3, 1000 mg calcium, 27-54 mg iron, monthly B12 shots, daily oral B12 twice a day (one B complex, then later one B 500), 10mg zinc. SCD diet.