What Causes Elevated Bilirubin Level,blood In Urine And Back Pain?

insight please on 15 yr old son 15 yr old son. 6 1, 165 lbs, athletic build. Plays football at the moment. Sunday evening he had a pasty look to him. Said he did not feel well. Stomach hurt. (figured stomach virus) He went straight to bed. Stayed home from school Monday. Said still felt nauseated. Threw up once on his own. Two more times he made himself throw up because he said he felt sick but nothing would come up on its own. Asked for something to help use the bathroom. Said stomach hurt but couldn t have a bowel movement. No diarrhea at all. Woke up during night complained of lower back hurting on right side. Said hurt to lay down or walk around. Slept with ice pack on back. Tuesday morning (today) said that he still felt sick to stomach and back was still hurting. Called Dr. office. Was told to take him to ER to check for possible kidney stone. Did a urinalysis which showed blood in urine. Cat scan was taken of kidney. Came back normal. Blood work came back normal other than a high Total Bilirubin which on The 12th it was 2.1 (previous blood work) and today it is 5.1. Blood pressure slighty elevated as well both on 12th and today.Was sent home from ER with Dx of virus and pulled muscle in back. Not sure I agree with the virus since he has not thrown up often or had any diarrhea. I do not understand why their was blood in urine but cat scan was normal. And why an elevated Total Bilirubin? ER doctor did mention Gilberts Disease as a posibility. Was told to follow up with his doctor which the apt. is not until following Monday. He is still in alot of pain on lower right side of back and when he walked by I noticed what looked like swelling on that side. Should I be concerned and push for an earlier apt with his doctor? I do not know whether to assume that it is just indeed a pulled muscle with a combination of virus or could something more be going on? I assumed he had a stomach virus when he was 7 and he ended up having strep that filtered into his kidney. He keeps wanting to take a hot bath to relieve back pain. He does not complain much even with the aches and pains that come along with playing football so I take notice when he says he is hurting. Any advice and insight would be appreciated. Thank you!