I have been out of commission since Tuesday night due to a case of food poisoning. Vomiting and loose stools every half hour for 4 hours (starting at midnight, Tuesday) and then loose stools all day yesterday.

Finally starting to feel better, but I weighed myself this morning, I am now at 158lbs. Before I weighed about 164.

Between losing half of my food intake on Tuesday and mostly water and Pedialyte yeasterday I have lost 6 pounds. That seems a bit excessive for one and a half days to me. Any opinions on this?

most of that is probably just water, you will probably gain that all back within the next week or so

I agree with Jaret, It's probably all water loss; in that short amount of time, I highly doubt you'd lose any lean muscle, and probably not much fat, either.

Joel,
A few weeks ago I had a bacterial infection. YUK! I couldn't even hold down liquids for 5 days! I went from 190 to 176lbs!! Now I'm back to my original weight and trying to gain more.

Glad you're feeling better, Sanchin. As of now I weigh 159, but I haven't eaten or drunk anything today. Probably is mostly water-weight, but I'll keep you guys posted.

yeah i agree with everyone else
water weight can vary pretty easily
just last night i went on a one hour run and i lost 1.2kilo just from that.

I got a infection I think too, been having a fever, lost 5 pounds in the last 2 days,sucks alot.

Well, weighed myself this morning, 160.5 lbs. So a total of about 4-5 lbs lost over the period of 5 days (and trust me, I've been drinking a lot of water to regain all I lost). Considering I didn't have a real meal between Tuesday breakfast and Saturday dinner, that sounds about right to me.