Abstract: Only bleeding from the uterus can render a woman niddah. At times, hematuria may be confused with vaginal bleeding. The physician can assist the woman by informing her of the presence of a UTI and of the possibility of resulting hematuria.
Discussion: Only bleeding from the uterus renders a woman niddah. Bleeding from other organs in the genital area does not. Occasionally, a woman may discover a red stain on underwear or toilet tissue and be concerned that it is from a vaginal source . If she has symptoms suggestive of cystitis (e.g., dysuria, frequent urination), a urinalysis and urine culture should be performed . If the doctor sees macroscopic hematuria or gets positive results from a urine culture, the woman should relate this information to her rabbi. In such a case, assuming that she is not expecting her menses at that point, the stain probably will not render her niddah.
Implications for Patient Care: If a UTI is suspected, the woman should be told that this may cause hematuria.
If a woman presents with presumed vaginal bleeding but has UTI symptoms, urinalysis and culture should be performed. If there are signs of cystitis or a positive culture, this information should be related to the woman, who can convey it to her rabbi for a halachic ruling.
 Kaunitz AM. Differential diagnosis of genital tract bleeding in women. UpToDate Feb 21, 2014.
 Gupta K et al. International clinical practice guidelines for the treatment of acute uncomplicated cystitis and pyelonephritis in women: A 2010 update by the Infectious Diseases Society of America and the European Society for Microbiology and Infectious Diseases. Clin Infect Dis. 2011;52:e103-20. http://cid.oxfordjournals.org/content/52/5/e103.long