I might know why Tiger is defecating beside the cookie sheet..... just a hunch............here is what I am thinking............I observe my cat taking a poop whenever I get the opportunity and it's all been about poop lately, which I don't mind. I have noticed that my cat digs deep into the litter for awhile, sniffs, turns around, digs in another place, and repeats this behavior until for some reason he has found the spot and then poops. I think Tiger can't dig because it's not deep enough and there might not be sufficient litter to cover it up. It's all instinctual. Then there is the pain factor too, which he is experiencing. My cat has been on a drug that has helped called Neurontin or the generic is Gabapentin. That is one theory. Perhaps buying a cooking sheet that has higher sides - one inch high or two inches high, to support digging and more litter but not to high to hurt him getting into the "litter pan".

Now, this website has ideas for litter pans and also, you can call and speak to someone who will listen and make suggestions about this:
http://www.drsfostersmith.com/

I just found this website yesterday and it goes into alot of detail about constipation:
http://www.felineconstipation.org/

Lastly, your vet might be another good resource for you too.

The more fiber you get into your cat, the better the poop will be, hence why I am using Miralax. I am not taking him off of his dry crunchies as that is all he prefers, but I have added food that is designed for hairball control along with his adult light food, it's high in fiber. Treats, I would keep giving but limit how much you give. After all Tiger needs to be appreciated and treats help.

Then there is the anxiety factor for Tiger. Have you heard about Feliway? It's a pheromone and comes in spray or plug-in dispenser. You can buy it online or at Petsmart/Petco. It helps reduce anxiety and perhaps consider purchasing this and spraying around the litter boxes and see if this helps.

BTW, I love your pics, sooo cute (((hugs)))

Keep posting