Starr used to poop outside of the box and at first I thought it was a behavioral problem due to stress. I later found out that it really was a medical problem. He began having severe diarrhea and he just couldn't make it to the box in time.

After I had some peeing issues as well, I added 3 more boxes and I also bought some cat attract litter and added this on top of the old litter. It's been working out great. Now I don't have to use the cat attract but I'm still using the feliway plugins. I don't know if these will help a cat that poops outside of the box though. I now have 6 uncovered boxes and only 2 covered boxes. Most of my cats now prefer the uncovered boxes. I hope that something will work for Oskar and hopefully it's not a medical problem.