constipation

can a cat with constipation eat lots?
my cat had poridge like diahrea for two days so we fed her some chicken and rice.
now i havent noticed her do a poop for about 3 days. i watch her get in the litter tray do her thing but when i look in the litter box i dont seem to find anything. and even if i do find a small poop i think it belongs to my other cat.
she is still eating lots of chicken and rice, she pees normally, drinks normally.
today we fed her a cream wich speeds up her bowel.
is it hard to catch a cat doing a poop?

Hmm... Maybe she's hiding the poop? lol. My vet suggested to me (for hairballs, but would work for constipation) to add some mineral oil to my cats wet food... because it can't be digested it sort of "lubricates" their digestive tract. Seems to work well for Toby's hairball issues at this point. Some folks on here have raised concerns about giving it by itself though (i.e. spooning it into their mouth) because it is tasteless, so might be inhaled. I think combining it with food solves that problem though.

I'd be concerned about a possible blockage, but if that was the case, she would probably refuse to eat and/or throw up.

Has she been in good health before this? Is she stressing out? You might want to try putting out a second litter pan as the other cat might be "guarding" the first and she's just "holding it". I have heard of this, but haven't experienced it with my cats. But, it would be an easy and cheap thing to try...I'd do that first, then try the mineral oil. If she still isn't going for 2-3 more days then go to the vet.
Art