I had a bladder neck incision with laser in late april 2016. Its been more than 4 months and i still get bleeding and blood clots in my urine. I am mostly constipated and situation is worse after a trip to lavatory. Antibiotics make me more constipated and i have to put a lot of pressure to pass stool and it really hurts the bladder then.
its rather unusual to get bleeding and clots after 4 months of laser treatment. it should actually stop within 21 days after the treatment.
antibiotics should be avoided. i suggest you to see a urologist and if required, get a ureteroscopy done to see whats wrong.