Not too nosy at all.
They only have a theory. They believe it started with a gall stone that moved to the pancreas duct and blocked it. The pancreas started leaking enzymes
into the body which seemed to attack his left lung. They believe the stone passed rather quickly but the damage had already begun. Him being a smoker ( not any more!) hampered the situation. His lungs filled with fluid and he was on antibiotics, none of which seemed to be working to reduce the fever. The pancreas slowly began returning to normal but the fever was not going down. They kept switching antibiotics to try to find the right one or combination of the right ones. Finally as his lung fluids began to diminish, the pancreas calming down and the right combo of antibiotics his fever started to drop.
However, with all the antibiotics he developed c-dif in his lower bowels because all the good bacteria was destroyed from all the antibiotics. That is now being treated and had no effect on his fever.
It was a catch 22. Time was of the essence so they weren't going to wait to find the "right " antibiotic so they thru everything at him. They will never really know what was the absolute cause or the absolute cure but this is their theory.
My son's pancreatitis wasn't anywhere near as serious, but after 2 ER trips, 3 days in the hospital and a bunch of tests, they never figured his out either. There were hints that it may have been caused by him taking Prilosec, which is an acid blocker he was prescribed for heart burn.
He started taking it Thursday before Memorial Day, Saturday he was in the ER and they diagnosed "gastritis" and doubled the dosage, by Memorial day he was having trouble breathing. On that second ER visit, they actually bothered to test his blood and found the pancreas enzymes and admitted him.
Sounds like your son's doctors did a great job thankfully, ours, maybe not so much. So awesome he is pulling through!