My 20 year old kid is ill, does anyone know what this could be?

[lilyofthevalley19]

For the past month, my recently turned 20 year old has been having some abnormal symptoms. Started w/ mild diarrhea, fever, and muscle weakness, and nausea. Since her friend came in contact with e. coli and she started showing symptoms not even 2 days after, we had a fecal test and blood labs done. E. coli came back negative and the diherrea subsided, but the occasional fever and constant fluctuating muscle fatigue/weakness remained and persisted until we took her to another doctor on Saturday. She'd also lost some weight. By Saturday morning the fever was back along with a new symptom of swollen lymph node in the neck and armpits and swollen left side in the upper abdomen. (3 days with the lymph nodes not improving) He examined her symptoms and labs, suggesting we take her to the E.R. because they couldn't do an ultrasound until Monday morning. The ALT (liver enzyme) were at 64, along w/ hemotocrit at 17. At the E.R. they performed several tests (blood, blood culture, 2 ultrasounds, CT scan and x-ray.) They checked for cervical cancer. A lot of these tests came back normal, except for slightly swollen glands in the CT scan. The only thing she was diagnosed with was BV, which she admitted to have been dealing with on and off for 3 years. She'd been taking Flagyl behind my back from PP, but only took 2 doses before the ER. We've been here since Saturday morning, now in the observation unit because her ALT has jumped from 64 to ~600 within the span of 3 and a half days. They don't know what is wrong, they've ruled hepatitis, STDs, HIV, mono, and all sorts of bacterial infections, and we're not getting any clear answers from anyone. They've sent an infectious disease doctor and now assigned a gastrointestinologist to look at her labs. They've taken many blood tests from my kid, and at times, her symptoms seem to be improving, but then she gets a fever again, most commonly at night. She's lost a lot of weight while here because she's completely lost her appetite. She hasn't vomited up any food yet, but she has "vomited" what seemed to be soda and something that looked like flegm. The lymph nodes haven't improved much since we got here, and they fluctuate in tenderness. Her stomach gets hot and bloated now sometimes, something I've never seen happen before in my life. They have her on various antibiotics, including for the BV, but they took her off Flagyl. I may have left out some details, it's been a long 4 days and we're still not getting any idea on what it is. Please help us.