Bowel Disorders :: Inflammatory Disease And Anhidrosis

My 27 year old son began exhibiting symptoms of inflammatory bowel disease about 2 months ago. He had severe stomach pain and his food wouldn't digest for several days. A CAT scan showed an inflamed ileum. He went to a gastroenterologist who ran more tests and put him on prednisone. The inflammation went away and at the last followup visit the gastro dr. decided not to label my son with IBD yet unless the symptoms come back. My son noticed that, since his problem began 2 months ago, he no longer sweats. Early on, he would get dizzy and light headed at work (it was September and still warm)but he wasn't and still isn't sweating at all. He goes to the gym for a workout and 1/2 hour later his face is bright red and his head feels hot and prickly, but not one little drop of dampness happens anywhere on his body. Since both the inflammatory bowel/digestive problem and the anhidrosis started at the same time, I wonder if they are related, and if so, what disease does he have? He is beyond frustrated at this point because his digestive problems aren't gone completely, and he has days where he's exhausted waking up after a good night's sleep, and has minimal energy a lot of the time.