I just read on wiki that ingesting carpet can lead to gastrointestinal blockage. I am not sure how much carpet would need to be ingested though for that to happen. My bunny did that a couple of times and I ran out and bought a bundle of the seagrass mats and placed them on the areas she loved to chew so that, in my head, she would learn to chew on the seagrass and not the carpet. But I did notice her ingesting it. But I caught her in time to stop her from eating too much.

My bun went through a horrible carpet chewing phase and actually ended up eating a great deal of it. She only had one tummy problem that required a dr visit but that was because I was feeding her too many carrots and it turned her urine red, which naturally scared the heck out of me!

IT IS NOT GOOD FOR HIM and IT CAN CAUSE A BLOCKAGE which is very very dangerous, however, if he is just nibbling it and spitting it out, my guess would be that he will probably be ok until you can cover it tomorrow. If he is ingesting it, try distracting him with some paper/a phonebook/veggies/hay etc.

If you have any 24 hr grocery stores around you, you can run to one of them and ask for some boxes. Try getting some from a cereal aisle because food items will not have been in contact with dangerous chemicals that could have leaked onto the cardboard and you can get larger boxes there. Remove all tape and staples and then just put it on the floor of his area. It doesn’t even really need to be covered in fleece, though fleece would be nice so that he has something warm to snuggle on. Chances are, he will dig at the cardboard.
Keep an eye on him and just make sure he doesn’t stop pooping and he keeps eating like normal and that his tummy doesn’t feel hard.

ingesting is dangerous but they normally don’t do that, they chew and spit. I find putting phone books on top of the carpet where they chew works-thy go to their spot to chew,. and chew the phonebook instead

Alas, don’t be surprised if they chew holes in the fleece, as well. I lined a fleece bolster bunny bed with a fleece blankie and though he loves to lay on it and groom himself on it, surprise! Little holes I found in it which he’d chewed. Sooner or later they do, it seems. But not too often, thankfully.

My girl bunny, Nelli, has a real problem with chewing on fabric. Especially if there are any strings hanging from something, she just gobbles them up like hay. I’ve found that she only eats certain rugs though- the softer ones with the rubber backing like you put in bathrooms are her favorites- the tougher and Berber style carpets aren’t as tempting to her. I recently had to go throgh the whole downstairs of the house and get rid of anything fringy or “stringy” so that Nelli can’t eat it. She’s always had occasion “pearl poops”- 2-3 poops strung together with fur/fabric/etc, but the other night she got a horrible bellyache that lasted for about an hour. I rubbed her belly and tried to give her simethicone (didn’t do too well though) and she got over it, but it really scredme. Later that night, she did some very strange, large oblong poops along with small ones, then went back to normal. But that made me think she must’ve eaten something that bound her up at least for a while.
It’s hard to keep track of what bunnies are into when they’re free range, but I try to keep an eye on all the rugs and furniture to be sure that Nelli isn’t eating anything she shouldn’t be. It’s the stuff with tough or long fibers or strings that really make me nervous. With other stuff, it’s more of a nuisance than a hazard. We all have mysterious holes in some of our clothes- she loves designer jeans in particular (my teenagers wear those- I wear jeans from the flea market- lol). And the fleece blanket that I keep on the couch has a Swiss cheese-like pattern gnawed in it.