It is possible for oral sex to lead to urinary infections. There are plenty of organisms in the mouth that may be a source of infections is oral sex is performed.
Certainly any type of anatomical abnormality in the lower GU tract can lead to more frequent UTIs. One can consider a pyelogram or cystoscopy to evaluate for this.
If there continues to be frequent UTIs, you can discuss whether staying on prophylactic antibiotics can reduce the incidence.
These options can be discussed with your personal physician.
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Kevin, M.D.
http://www.straightfromthedoc.com