Sure, part of the job of your intestines is to deal with the water in your food. Espectally the large intestine, if I remember correctly. However… I wonder what your plan is to hold it in. The whole point of diarrhea is to flush everything more quickly through your intestines, and then out. That’s why it’s still wet at the end. You’ll get kind of a traffic jam at the rear end. With more incoming. And I don’t think the intestines are designed to withstand pressure. And the sphincter isn’t really meant to hold back fluids…

So no. You need to drink a lot to deal with the dehydration. In bad cases the doctor can connect you to a drip. Those will be things that have an effect.

And all of that happens with a reason. I suppose you can force the intestines to stop with the diarrhea by using some medication. But then the pathogens/viruses/whatever your body is trying to get rid of, will grow inside of you, and you’re bound to experience other issues.