All food is liquid, called chyme, by the time it exits your stomach. (Yes, there are exceptions due to things not working well.) At pretty much the end of the transit, water is absorbed from the chyme. A well-functioning colon will make well-formed stools by eliminating all but the right amount of water. Constipation means that too much water has been removed. Diarrhea means that not enough water has been removed. (That's why people get dehydrated from diarrhea.)
Your whole digestive tract, from mouth to anus, depends on a bazillion different functions, starting with the smell of food, it's taste, the physiobiology of chewing, and the mystifying number of biochemical signals that tell each cell what to do.
Let's say you want to take juices. Then, you are depriving yourself of one of the first digestive signals, chewing. The tongue is a rich array of sensors that trigger chemical processes later on in the stomach. If you drink juice, you're saying, "Screw you, stomach, I'm going to dump some shit in you, and you won't have a clue what to do with it!"
Other dietary extremes wreak other kinds of havoc, like unbalancing your colon's bacteria types, losing or retaining water, or upsetting the mineral balance in your body.
I'd say: Constipated > eat normal amounts of food.
Normal amounts never mean "full" or "stuffed." Eat until "satisfied."
Then, once everything is going well, you can see what comes out.
P.S. I've had pelvic floor dysfunction. I had an operation for it when I was in my 40s. It came back, but never bothers me since I've been eating raw paleo style. I've also have autoimmune issues in my gut, but the usual symptoms have completely healed on this diet.
I switched, cold turkey, from cooked food to RPD. I started feeling better from day one.