What Causes Vomiting And Upper Abdominal Pain?

hi, I have intense pain in my upper abdomen - right under my ribs so severe that I am unable to sleep - it also causes vomiting. I have it for about 5 or 6 hours and then am fine for a few days or week. it is getting more common and more painful as times goes by. my first bout was in November. have had 5 bouts usually at night but today it hit during the day and I had to leave work. what could this be??