5 year old cat suddenly constipated...help!

My cat Chai is suddenly experiencing constipation. She keeps squatting like she needs to poop but can't. She's doing this all around the house with no success. Obviously most vets are closed today (Sunday), including her regular vet. Is this something she needs to go to the vet for or is there something I can do for her? She doesn't seem to be in pain but I know cats hide that well.

Thanks.

She really needs to see a vet.  When they get to this point they usually need an enema to get things going again.  Been there done that.  Many kitties when they get to this point will become nauseated and quit eating which causes other more serious issues.

There are some things that can be done to prevent it in the future.  It's kind of a trial and error thing but the main thing that helps all kitties is increasing fluid intake.  Wet food helps and some kitties will drink more from a fountain.  If your kitty isn't interested in the fountain, one of mine wouldn't use one, putting bowls of water in several places will help.