Different doctors are going to give you different answers -- but within a certain rubric.
The prenisone isn't going to help with sleeplessness or anemia and probably isn't the best answer for fatigue, although it may take care of that initially.
Your son might try a different 5-ASA than Lialda. Maybe the Imuran will be effective.
My first GI liked Asacol and that was about it. His philosophy was to learn to live with whatever symptoms I had as a long as I took Asacol.
I've had a number of GPs and they been all over the place.
I've had my current doctor for a number of years and he's a big, big fan prednisone. I avoided the pred and, by switching to another 5-ASA, I've discovered the Asacol wasn't working, so prednisone would have only made the situation worse.
I saw a new GI this week and he's a big fan of Imuran and thinks I should be on it rather than sulfasalazine. I'm not going to take it the Imuran, but he suggested starting it without prednisone and doesn't like to use steroids at all. He also said he counsels his teen and 20-something patients to consider surgery in the short term and usually doesn't suggest they take Remicade.
So -- four or five doctors and four or five opinions. The best thing that has worked for me is to be informed and to know what to expect -- as best I can, anyway.