My UC is located on the left side too. I'm currently in Remi remission, and have as many movements that you have per day, so I'm thinking you are doing pretty well right now...but everyone has a their own perspective of what feeling well and remission is. I think I'd just stay in touch with your doctor if you have symptoms that worsen and it sounds like your doc is on top of things by doing a stool and blood test.
As for the accident, I'm sorry that it happened, but I cannot say for sure if the stress and meds from that could have caused the UC. I'm not sure any of us know what the cause really is!