You mean an underlying disease like not drinking enough water?
Nope ..but how about colonic ulcers or lacerated colon ..or irritable bowel syndrome or certain kins of diabetes, or lymphatic deseases..etc etc ..the list is long ..hundreds of things that can cause dehydration , and that are not simply "not drinking enough water"..
And that if the person merely buys bottled water with "prevents dehydration" on the lable, and leaves the underlying condition untreated..can actually kill them..
Most people eat and drink total crap, ( I know..for many years I made a very very good living inventing making the ads that hawked it ) ..and generally treat their bodies as if they had another 10 or so ( for spares ) socked away in a cupboard somewhere..They spend more time and concern on washing and waxing their cars* than on keeping the bio-machine they are doing their thinking from inside of healthy..
*present moderators excepted..I hope ;)
What the heck is it made of, H30?
Distilled tooth fairy tears ..says so ..right here on the bottle label..if I'm allowed ( after brib^^^^^lobbying ) to print that on the label..