Constipation in crohns

I was diagnosed having crohns last year and life has not been the same ever since. Unlike the moat common symptom, I suffer from constipation ir more so strained stool problem. Eating the right food has been the major issue. I am unable to digest fiberous food, salad, high protein food like fish, egg and chicken. I have been responding well to light pasta or risotto but that too is not consistent. I have severe stomach pains after eating dinner. At times the pain and discomfort is so bad that I think I should stop eating dinner ..... Any suggestions or help ??