As we all know, our intestinal trackt is (mainly) divided into 3 sections: stomach, small intestine and the colon. The stomach mainly breaks down the food physically and chemically. The small intestine absorbs nutrients (and breaks down the food even more) and the colon dehydrates the poop, to not waste water and to get a bit more suitable consistency. It also saves space if you dont have to store all the water.

So you can absolutely drink water through your colon. I wouldn't really recommend it, since theres the danger of you accidentally pushing back your stool which isn't that good, but you can do it.