I would stop all antibiotics and if your GI symptoms did not resolve in a day or two, I’d look for another, possibly more serious cause
for these symptoms. Rifampin has been known to cause
liver, renal and pancreatic problems, though not commonly.
Semen is usually sterile and represents fluids from your testis, epididymis, vas deferens, prostate and urethra. Therefore, let us not only give attention to your prostate. I would want to know about your urine culture also.