Why aren't obligate carnivores all constipated?

That is to say, what biological mechanisms to they have that humans don’t, that allows them to forgo roughage?

Same as me.
Their intestinal tracts are shorter. They do not retain the contents as long and not nearly as long in the last portion, the colon. Mine has been removed along with a portion of the small intestines. I have a very carnivorous diet now and never have constipation. Quite the opposite.

They evolved. Probably due to the available food sources. The ones that happened to have shorter tracts were more likely to survive on the diet and passed on their genes.

I am not passing my likely faulty ones forward. Snip.

Also, carnivores ain’t eating steaks. The gut contents, the fur, the bones, all act as roughage.

I’m with Kedikat. There’s nothing that passes through my intestine quicker than a can of sardines or a bowl of oxtail stew (both of which I find delicious)!

They drink a lot of coffee, particularly the nocturnal ones.

And you’ll find that very few carnivores are heroin users.

My obligate carnivore also gets Miralax in her water, on the advice of my vet.

On a more serious note, their bodies are designed for eating and digesting meat, and only meat, with a bit of vegetable matter that comes with it.

Designed by whom?

I’m being facetious, but I always avoid this phrasology. For obvious reasons.

Constipation is not an inevitable consequence of lack of roughage, even for humans.

Cats and dogs both eat grass when they need the roughage.

Maybe they are constipated. That could be why many of them are so cranky.

Why whom? Why not what? Designed by evolution.

Whereas human beings are designed to eat lots of fiber. It’s why we have three stomachs and chew our cuds.

The word “designed” implies a designer. Or at least, a purpose or intention.

Moderator Note

I don’t think that anyone in this thread is actually proposing a “designer” for digestive systems. Since this is turning into a bit of a hijack, let’s drop the design/designer discussion and focus on the actual OP, which is carnivores and constipation.

Those who wish to discuss design/designer issues are free to start a new thread.

ETA: Evolutionary processes such as selection are of course relevant to the discussion, so things that are relevant to the OP are of course still welcome in this thread. Let’s just avoid the hijack that is mostly a matter of semantics.

Imagine some poor cat having to dive into the Worst Litter Box in Scotland.

Huh, really? I’d always heard that you need to eat enough fruits and vegetables or else you’ll get stopped up.

That’s not my experience. Sure, my kid sister ate nothing but one hot dog one summers day, and was in crying pain that night with constipation. But if I eat several slices of a roast, rare, and nothing else, I will still defecate without a problem. It amazes even me, the volume produced, when I believed what you believed.

OK. That could be: connective tissue, undigested meat, fats that I can’t utilize rapidly enough, bacterial mass, excess water, and the remains of some vegetable roughage I had before that day.

All of which, has been established, obligate carnivores have access to.

That’s a common idea. And some people might get relief from constipation by increasing fiber intake, but it is definitely not universal. Here’s a study where participants improved when reducing fiber intake: https://www.wjgnet.com/1007-9327/full/v18/i33/4593.htm
And the information I can find for all meat diets indicate that constipation might be a problem, but not that it is guaranteed.

Sorry, my fault. A pet peeve in science communication fields!