Anyone ever dealt with colitis in their cats?

My one year old baby was diagnosed with colitis today.  I wonder if it can be related to him having his glands squeezed on Friday or if maybe he started going outside his box because he was starting to get colitis before Friday.  How did you deal?  Was the colitis a one time thing or is it something that continues to reoccur.  How much pain is my baby in, or was in before the vet prescribed pain meds?  Anything else I should know?  Thanks and God bless.

Colitis can be a serious condition if left untreated. Did the vet find the cause of the flare up? It could be caused by parasites, bacteria, algae in water, foreign items that have been eaten and even cancer.
Is his poo solid or runny? Colitis is a thickening of the walls in the colon, making it almost impossible to absorb water, creating runny stool. This can severely dehydrate him, make sure he is drinking plenty water.
Is he going to the bathroom frequently? Straining?
These are all signs of colitis. If he doesn't have any if this, it may be something else.
Since he had his glands expressed, it may be some anal sac fluid that may have gotten outside of his litterbox. My cat has a problem with her glands, and it often leaks.
It's a very foul odor, usually brown in color.
I would go back to the vet to have a full rectal exam.

Not sure what you consider to be a full rectal exam. He had been pooping like every 3-4 hours after the glando squeezing. The vet examined him in the back. She said they had to muzzle him and wrap him in a towel. He was very sensitive down there and very raw and irritated. He is currently on antibiotics and pain pills. I just hope and pray this is acute and not chronic.