My girlfriend is having pain in upper left quadrant and back, headache, nausea, fatigue, loose bowels. she has no insurance. what could this be?

L abdominal pain: The majority of left side abdominal pain in young adults is due to constipation. (they are too young for diverticulitis, which is the other major cause). Is there any history of constipation? If constipatoin gets severe, sometimes new liquid food from the stomach leaks around the blockage, so it is not obvious that constipation's the problem. If there is past constipation, try miralax, (polyethylene glycol) 2 tbsps/d.

Many possibilities : It may be stomach flu or food poisoning. Pancreatitis strikes in the luq but usually causes nausea & vomiting. Does she drink alcohol excessively? Have her gallbladder? If the answer to these are no then pancreatitis is unlikely. There are other less likely causes. Regardless if the pain is severe such that she is doubled over, has fever and has pain with movement she needs evaluation asap.