Constant Meowing and Straining to Poop?

Just a week ago, I took my 8 year old cat, Asti, to the vet for urinary tract problems. They said he didn't have a blockage & was just irritated. They gave him Amitriptyline & made me switch to Hill's Prescription cd diet. He started doing a lot better & peeing larger amounts. Now, all of a sudden, he won't stop going to the litterbox & trying to poop (I think). He has diarrhea & keeps meowing. I needed to wipe him & he got extremely upset when I touched him. If anyone has any insight, please let me know. He's never had so many problems before.

He was just eating (mostly canned food) & drinking normally right before this happened & hasn't thrown up. I think he might've eaten a bad batch or something & his stomach is upset. He's sleeping on my lap now.

it probably the sudden change in food. cats and dogs can get upset tummies  when their food suddenly changes 

I also thought that but I started him on it a little over a week ago & he didn't have any problems. I would take him to a vet but I've had to go 4 times in a week & it's really killed me financially. I guess I'll watch him for now. He seems to have chilled out now. Thank you for your insight.

keep eye on him if he still have problems for more then 24 hours or it get worse or he become lethargic take him to the vet

Okay; thank you again.

You know what four times in a week and they should be cutting you some major discounts - like free maybe. 

I can't see how it would take a week for that kind of reaction.  You might be able to find something cheaper and just as effective as the hills PD.  You can search the site threads for suggestions.

Well now I'm all stocked up on it. They have been cutting it cheaper, but I'm in college and money is kind of hard to come by right now. He's had a similar reaction before when he ate a bad can of food but at that point he was vomiting & there hasn't been any vomiting this time.

how you storing the dry food? 

how often you clean his food bowl and water bowl?

I clean the dry food bowls every month, the wet food bowls & water bowls every day. The food is stored in cabinets.

clean the bowls again if you haven't already

Yeah, I stocked up, but I did end up returning a case back to the vet after I changed.   If it's the case that's bad then you'll just end up with another vet bill when he eats it. 

They should be cutting it cheaper, if I took my car into a mechanic four times in a week and he wasn't finding what was wrong I'd consider that I was due a freebie.

yeah it probably due to bad batch 

He's eaten other cans from the case & didn't get sick from them.

maybe it from that one can