Although a K pouch differs from the J, I also struggle with dehydration. First some suggestions and then, if you stick w me, a theory.
Suggestions, based on my experience and/or research: So long as you can tolerate milk, it is an excellent source for dehydration. Another source is coconut milk as absorbed better than water by intestine.
For those loving Gatorade, please read ingredients. First is sugar and not lots of electrolytes. One might consider getting electrolyte powders and add to water. They have less or no sugar and easy to carry around. Or make your own. Recipes on line.
If you have muscle soreness and/or cramping you are experiencing a dehydration symptom. So too is dizziness. If both get worse, you can't make sense of anything nor make decisions, head to the ER for an infusion!
I take salt tabs, up to 4 g daily in the summer. Then again I have a K and also CKD. Salt/sodium is an electrolyte.
Staying out of direct sun helps me.
My personal theory is--understandably untested so don't blast me on this--based on fact that stool w colon differs from stool w/out colon by amount of liquid. Liquid, with colon, is absorbed by our bodies. Yes? And it is absorbed on a 24/7 basis. According to my theroy, when lacking a colon, the expelled liquids in watery stool means that fluid was not absorbed. I am assuming the absorption happens through osmotic transfer into the body's cells. To compensate we need more liquids, whether from water or fruits or the such. Ok, this is where I might be criticized for going out on a limb--when we consume additional liquids, those liquids expell more electrolytes through the kidney, so that they too are not absorbed. Hence that's why electrolyte additions to our liquids helps keep us on track. Curious what others think of this.
Sorry for length, Jan