Have minor burning after urination & ejaculation. No STD present. Doc. Prescribed flomax and cipro (ciprofloxacin). Why burning after? What could be at the origin of the burning?

;H change. Either changes the ph in the urethra and the local infection can cause irritation to the lining so it is more noticeable. The Cipro (ciprofloxacin) should clear things up in 2-3 days.
Burning urine. Hi there are several possibilities: the testing could be a false negative. The Cipro (ciprofloxacin) was not the best choice since it does not cover chlamydia well. There is significant evidence that gonorrhea is becoming tougher to treat and you may need an injectable med for this. I am unable to tell your sexual orientation by your questions but msm's should always be treated for both gc and chlamydia!
Prostatitis. Inflammation of the prostate usually due to infection.