Oops... forgot to mention that the illness started this morning and I was actually doing okay from about 4 - 9PM, but then I tried to eat which, apparently, was a bad idea.
This is what I do, assuming that we are talking about the same thing.
The runs, feeling generally sick and weak, maybe even feverish.
I go with a remedy taught to me by our local vet, many years ago, before it was possible to find an actual real doctor who truly knew what he was talking about.
The treatment is based on PH balance.
The idea is to make an unfriendly environment for the bacteria/microbes/parasites, while still being friendly enough for you.
The way to do this is with lime juice or apple cider vinegar.
Also, one should starve the little buggers out, so eating is not on the menu right now.
That being said, one can and should drink as much water as possible, perhaps even some electrolyte solutions and bananas go down well, for some reason.
I forgot to mention, that I immediately take Immodium, just to plug up the "hole", pardon the expression.
If you don't plug it up, you will dehydrate and make it worse.
Avoid coffee and tea like the plague.
Once you are getting back on your feet again and are starving for solids, go at it easy.
Eat whatever goes down easily for you (in my case, it's spaghetti) and eat small portions with greater frequency, rather than 3 big meals per day.
Keep up the lime juice or vinegar treatment until you are positive you have won the battle.
This solution works for me 99% of the time.
In more severe cases, I will get onto Ciprobiotic 500 for a week or so.
Go back & challenge it.