I too have a male cat (4yrs) who had a blockage at 2, and has been on prescription food since, to keep the urine acidic, preventing the formation of crystals, thus decreasing likelihood of him blocking again. however, from the research I've done, Feline Lower Urinary Tract Disease.... (FLUTD) is fairly common in male cats, once the first issue has occurred. I've posted a link to my issues with jak:http://www.thecatsite.com/forums/sho...d.php?t=232378
While everyone/pet is different, I would definitely re-visit the vet and have a sterile C&S (culture & Sensitivity) sent out. That way, even though it takes time to grow the bacteria, they can determine precisely what organism is causing the infection & ensure they get ur baby on the proper antibiotics.
Also, I've found when Jak had a UTI (or whatever he did have, flare-up's of cystitis/inflammation) a sedative medication was nice to relief the discomfort. This way, he didnt have the urge to go all the time & didn't really feel the pain.
It is odd that he's doing it rite around/on you, like maybe he is sorta mad at you & is trying to mark his territory/you as his human???
There is a great wealth of info on this site! Are there strays around the property? UTI? Behavioral? Recently moved, adopted new pet, new baby/member of the family? New neighbor dog? Any other new stressor? Not seeing enough of you? Change in diet/diet habits? New location of food/water or litter box? Any tiny, minor thing can stress a cat beyond what we think is normal. Use this site to do research. Crazy things can work: Orange/citrus smelling potpourri/home fragrance, aluminum foil, using blacklight to find old stain/marked areas & cleaning it out completely...the list is endless!!!
Good luck, please let us know what happens!!!