Ooh....I feel your pain. I got a horrendous case of food poisoning last week. (The preservatitve/nitrate free bacon doesn't last more than a day or two in the fridge!!) I know that once you have had a marathon session of puking and diarrhea, your potassium levels and electrolytes are really depleted and you need to get them back up of the puking/diarrhea will continue. I got some Gatorade, sprite, and chicken noodle soup and DID NOT CARE about the carbs, only about feeling better. I couldn't even keep water down, and the thought of my regular low-carb foods sent me into dry heaves...ugh..
Don't worry about the carbs....just get yourself better. Ginger Ale is really higly recommended for the nausea/heaving stomach.