Equine question

Hello, my 16 year old thoroughbred I’ve noticed stands Parker occasionally like he needs a wee. I’m very curious as to why he does this. He doesn’t do this when he is in the field only when I get him out to groom he does also stand in his stable with his bum against the wall, but yet again doesn’t do this in the field against anything. He doesn’t act like he is in any pain along his back at all, and when ridden he’s slightly stiff to begin with but he’s been this way for a while due to his age and soon loosens up after a warm up and is not always stiff to begin with. A few years ago he did fracture his splint bone but had the chip removed and had a year of no ridden work had 4 months box rest and was turned away for a further 8 months and has been sound and back in work for a year now and got 100% all clear from the vet. I just want to know why he sometimes stands parked and why he occasionally puts his bum against the wall in his stable, could this be something to do with needing his sheath cleaned?

You need to call your veterinarian.

got 100% all clear from the vet.