Suggest Treatment For Persistent Vomiting

I have been vomiting since Monday, March 12th. I have not been able to calm the vomiting down even with the addition of Zofran of which I took the first tablet on Wednesday night at 11pm. I took another dose today, Thursday, March 15th. At this point I still cannot hold anything down except very small amount of jello (4 tsp) sips of water, sips of ginger rale. My recent history which includes obstructive bowel surgery (11/08) and another episode of bowel obstruction on February 24th of which my surgeons decided to insert an NG tube vs doing the surgery. It did work in taking care of that condition, but now here we are with more trouble, but there is very little pain with whatever is going on now. I also had a bleeding ulcer in my history (Sept. 2012) which was resolved by cauterization during endoscopy. Please help. I don t know what else to do.