Please read the article on Stains for an overview of the theoretical concepts referred to in this article.
The most common staining questions arise when a woman finds blood on toilet paper. The easiest way to avoid such questions is to avoid looking at toilet paper. There is no obligation to look at toilet paper, and the easiest strategy is not to do so.
If a woman does look, and sees red staining, she should ask a specific halachic question about her status. She can ask a question even if she has already discarded the toilet paper. However, if she retains the paper, being able to evaluate the shade may provide grounds for leniency. The answer will depend on several factors:
Is she Ashkenazi or Sephardi?
Sephardic authorities generally rule that blood on toilet paper does not make one niddah.
For Ashkenazim, the issue is more complicated and the ruling will depend on the factors below.
How soon after urinating did she wipe herself?
For those who follow Ashkenazi rulings, if a woman wiped within seconds of urinating, then we suspect that the sensation of urinating may have masked a hargashah. In that case, barring other mitigating factors, a stain on toilet paper would make her niddah even if it is smaller than a gris.
There is a range of opinions among contemporary authorities as to whether and for how long one needs to wait before wiping in order to be lenient. Some rabbis do not require any delay; others require a minute or more. We follow the opinion that if she waited at least fifteen seconds after urinating, she may disregard any stain found on the toilet paper.
What rulings does she follow regarding toilet paper?
Contemporary authorities generally maintain that toilet paper or tissue, which is flimsy and meant to be discarded immediately after use, is not susceptible to ritual impurity (mekabel tumah). Stains found on such a surface are generally treated leniently.
However, there is a range of opinions regarding blood found on toilet paper used to wipe the vaginal area. Some authorities are strict because wiping is somewhat similar to an internal bedikah or for several other reasons. In some cases, rulings may be more lenient if the toilet paper is colored rather than white, or if the stain is smaller than a gris (about the size of a U.S. dime or an Israeli shekel). Again, we follow the opinion that stains on toilet paper may be disregarded if she waited fifteen seconds between urinating and wiping.
What was the color?
Not all colors make a woman niddah, so another relevant factor is the exact shade seen on the paper and the lighting conditions under which it was seen. For example, artificial light can often make colors appear pink or reddish that would not look that way in daylight.
Was the Discharge Uterine?
A last relevant factor is whether there is another possible explanation for the bleeding. For example, women suffering from a urinary tract infection or yeast infection may have bleeding attributable to the infection. So too, a woman might have hemorrhoids or a vaginal lesion to which the bleeding could be attributed. If bleeding can be attributed to a non-uterine wound, it is considered dam makkah, not dam niddah.
Please see the section on Bleeding from Trauma (Dam Makkah) for a discussion of the laws that apply when a woman suspects that the source of her bleeding is non-uterine.
Wipes are treated like toilet paper with respect to these halachot.
Cases in which blood is seen on the toilet bowl or seat, or in the water are generally treated leniently. But when blood is found there within fifteen seconds of urinating, and a woman follows Ashkenazi halachic rulings, a question should be asked.