It could still be a
stomach virus, however, it could be a bacteria or even parasite. I recenlty had a
stomach virus that lasted about 7-8 days.
Have you ever been tested for or diagnosed with IBS (Irritable Bowel Syndrome)?
Your headaches could very well be a sign of dehydration - with all the diarrhea, you can get dehydrated pretty quickly. Be sure and stay well hydrated - water, ginger ale, sports type drinks are all good.