I Have A Pretty Complicated Question, But Was Wondering If

I have a pretty complicated question, but was wondering if I could get some help. My dad is currently in the hospital and no one can figure out what it wrong with him. He recently traveled to Ireland for a week. A day before he left he complained of stomach pains, with feeling of fullness/bloating, and loss of appetite due to this sensation. While in Ireland, he experienced fatigue, fever, and loss of appetite due to bloating and feeling full. He claims he ate very little (maybe a cup of soup per day) while on the trip, and gained 6 lbs. Upon returning home, he continued to feel fatigued, and his urine turned brown. He also continued to have a fever of 101 or so. He was admitted to the hospital, where they completed a Barium swallow test (they thought he had Diverticulitis) there were only signs of diverticulosis on the CT scan, no diverticulitis. Also, a small, non-blocking renal calculus was noted on the report. No other significant findings of the CT scan. His labs showed slightly low Calcium, RBC, Hgb, Hct. All other lab findings were normal (WBC's were normal.) His LFTs were slightly elevated. His blood cultures did not grow any bacteria. His hepatitis test was negative. He has continued to have a fever close to 102 every day. He was started on IV azithromycin and metronidazole, but the fever has continued. His feeling of fullness and fatigue has continued as well. He was finally discharged with an rx for oral azithromycin, metronidazole, and protonix. He continues to have the high fever, and finally saw an ID doc today - they drew more labs and his LFTs have continued to worsen. They have re-admitted him and are not sure what he has. They are scheduling an ultrasound of the gallbladder and an echo of the heart, but have no answers at this time. Any ideas/thoughts would be appreciated. I am a PharmD, so I know that his antibiotics undergo hepatic metabolism, but I'm getting worried about his possible diagnosis....