Cat urinating outside of box

Hi all.. our Jax cat saga continues.

In May DH and I went away for a 10 day trip. The cat sitter came by twice daily to feed/play/scoop boxes. Upon our return, Jax started urinating around the house. We've taken him to the vet twice - they said his bladder looked a little inflamed. We've done two rounds of antibiotics, pain meds, switched him to science diet UD wet food, get a water fountain, have had a feliway in for a few months, new boxes (we currently have 5 out), cat attract.. and so far it's been hit or miss.

Anything else I can do? We are at our wits end.. we love him but it's so depressing to always smell cat urine. We do use nature's miracle to clean everything up.

The last time I saw him use the box was last Thursday - he did a big pee in it.

Any other suggestions are welcome.

For some background to experiences with Jax since bringing him in to his new home you can see some here, and here. 

There's a free online seminar coming up in two days that might have something useful for you. 

http://consciouscat.net/2016/07/22/free-teleseminar-wont-cat-use-litter-box/

Thank you! I've signed us up for this.

Is he castrated? And most importantly, are you sure he is?

My male cat had a problem of regularly urinating out of his litter box, and sometimes had his poo.

We were told he was castrated when we adopted him, we'd also took him to cople of vets, they checked his sexual organ and they all said he was castrated; until one day.

2 years ago I took him to one of the best veterinary clinics in town, and an experienced vet told us some male cats, during their first months can have problems about sexual organs. He said my cat's organs were "stuck" inside and couldn't find their way through his back and reassured us by doing having an ultrasonication.

Our cat had a major operation, but hopefully his genitals were taken out and then he was fine.

Until then, he's been urinating and pooing into his litter box but nowhere else.

My advice is, take him to the best vet clinic around who has a surgeon or a professor in their crew.

Best of luck.

Hi, he definitely is as he came from the shelter. 

Thanks for the suggestion - we will schedule another visit.