Findng poop in other places than the litter box is not that uncommon in Manx cats due to the deformity of their spine. Here's a quote from a web site: "Manx cats are prone to fecal (stool) incontinence because they are often missing part of the nerve plexus that controls the rectal area as well as missing a tail".

My Manx is nearly 2 yrs old and I sometimes find poop in front of the box or in the hall way. This is because her recal area wasn't able to fully expel the poop (sorry for lack of termonology!) and when she jumps out of the box, it then falls off. I have also found her walking thru the house with the poop still dangling from her anus!
I'm surprised you haven't found poop elsewhere before, but either way, keep an eye on your guy since it could be a colon problem, something Manx can have problems with in their later years.

Definitely put in a night light for him, especially since his sight could be failing.

At 16, I wouldn't be at all surprised if your old boy has some arthritis in his legs and/or spine. If that's the case, it may be uncomfortable or even painful for him to negotiate stairs and/or step over the lip of a litterbox. I suggest you place a litterbox or two upstairs and choose litterboxes with lower sides to make it easier for him to access and use them. You might also consider a glucosamine supplement. My dog's orthopedic surgeon is very impressed with a glucosamine supplement called Dasuquin, which he has seen have very good effects on his patients with joint problems.

I also strongly recommend you go to your vet and obtain copies of all of your cat's lab work to look over yourself. It's surprising how many vets disregard or overlook "borderline" lab results, effectively eliminating the opportunity to address chronic diseases in the early stages. IMO, everyone should always request copies of all lab work run on their animals and maintain their own health files at home. It's the only way that owners can really stay on top of their own animals' health.

Laurie

I too have a Manx who I noticed starting 'missing' the box a few years ago, and kind of leaving a little trail :( . And like you I thought at first that she was not making it to the box so I considered putting even more boxes around so she wouldn't have to go very far to find one. Until I noticed her racing away from the box, and you guessed it... leaving a trail. Turns out, she was constipated and it hurt her to poo. She ran from the pain. Which of course meant she deposited her poo wherever she happened to be running. So I had to find ways to get more water into her. I gave in and allowed her to drink from a constantly dripping bathtub faucet, her favorite way to drink. And I have to feed her wet food mostly. It worked. Unfortunately she developed an aversion to the box to poo that she hasn't overcome yet. She uses it fine for #1, but I have to keep an eye on her and actually take her to the box and keep her there until she goes #2, which doesn't take long. And then when she is done she races from the room as though the box is going to swallow her. It's weird, but it works. So, as odd as this question sounds, can you tell which direction the poo is facing? LOL, without getting into the gory details, sometimes if you look you can tell. Maybe your kitty needs even more liquids than he is getting now.

At 16 years old I would say that more then likely the stairs are getting very hard for your cat to get down. At his age he needs a box on the same floor so he can get to it quickly... Also if he has not been eating canned and has started that lately. The diet change is also making him have to go more urgently ..
He's a senior cat and really needs a little box he can get to easily and quickly. I doubt if he's missing the box as its more he's just not able to get there in time due the the stairs and his age..Just like we people as we age we need things made easier for us..

If your cat were a human he'd be in his mid-eighties. If he were a human he'd be inundated with junk mail every day concerning Depends, hearing aids, vitamans, Gingko biloba. IOW be thankful he's healthy and all of us who have had senior animals probably have dealt with those issues occasionally.

I can say that what laurief and jackieblue said rang a familiar bell. My siamese/tabby cross made it to twenty I believe. Her labs were normal or nearly so right on up to the very end, but sometimes borderline because her body was compensating for the lack of efficiency caused by age. Nothing jumped out at the vet on which to take action, but it was obvious when she became symptomatic she was mildly dehydrated for a long time and her kidneys finally failed. She had some good years before that happened, however. My male tabby had colon issues as he got older. My dogs had toileting issues as well as they got older and we just dealt with it as best we could to keep them comfortable and mimimise the occasional mess. And yes, stiff joints and decreased mobility and nerve issues (what my male tabby had) can present like that. If you'd ruled out something acute you may be dealing with effects of the aging process. I think you are wise to include as much moist food and access to water as possible.

A friend of mine has a 16 year old cat that's doing that, and she's not a manx. She says it's just age.

Thank you all for your responses and suggestions. I guess I just hate to think of Mr. Bear as getting old and near the end of his life. We lost our other dear house cat two years ago from lymphoma at 14 years old and I still miss him so----I hate the thought of now losing this cat in the perhaps near future!

Thanks again to everyone and I will try many of your suggestions.

If it is age related, it certainly doesn't mean the end is anywhere near. I'm 65 and my systems are just starting to slow down and I don't expect to 'check out' anywhere soon. ;-) Two years ago, every pet in my house (seven of them) was geriatric with the exception on one nine year old cat. I just found out that potty issues often came with advancing age and it's not at all an infrequent occurance. My mop and container of germ-killer was my best friend. It's an accomodation you make to those you love.

Just enjoy the moment with your pets, and don't dwell on their eventual departures. We all know when we acquire them, that good-byes are likely to be part of it someday. The connections we make are worth it.