In serious trouble.

[4IM]

I'm 17 years old and about 4 months ago I had an attack - it involved constant vomiting and diarrhea. I ended up calling an ambulance as I was pretty out of it and passed out on my kitchen floor, none of my family were home at the time. It took 3 drip bags and 5 needles to make me eventually feel better (after 9 hours) although they wanted to keep me overnight. They took bloodtests and urine samples - results came back with nothing out of the ordinary. They said it was probably just a case of food poisoning.
But it happened again, 3 more times. Same old story, did more tests - still nothing. I've lost about 10kgs in 4 months from this constant vomiting and trust me I DO NOT want to lose weight, I weigh 41kg now, which is incredibly underweight.
Now I'll get to the point - I haven't had any recent attacks since early last month. But I do vomit at least once a week. (might I add I do not force myself to vomit at any stage)
I found that I usually start feeling nauseous after standing for a long period of time? I don't know if that means anything, i get a pain in between my ribs but lower and on my sides usually after i've started vomiting. I know if i can't find out whats wrong I will lose my job and lose a lot more weight therefore only becoming more and more unhealthy. I can't think of anything else to turn to, PLEASE HELP.

[4IM]

I do keep myself well hydrated, but all the times I went to hospital I was severely dehydrated due to vomiting and diarrhea. Thank you :) I'll be seeking help this week as I'm now unable to even work! I appreciate the answer :)

[4IM]

I do keep myself well hydrated, but all the times I went to hospital I was severely dehydrated due to vomiting and diarrhea. Thank you :) I'll be seeking help this week as I'm now unable to even work! I appreciate the answer :)

[mammo]

This can all be caused by being dehydrated....are you keeping yourself well-hydrated?  Not just with water but orange juice, and low sugar Gatorade.  But with this continuing you need to see a Gastroenterolgist as he can get right to the problem.  This may take more than blood work and the intestinal tract is a GI's specialty.  Don't wait on this, get help.