Five conditions for a stain that renders a woman temei'ah: size, a surface that can receive tum'ah, a white surface, location, and a problematic color. Now the last criterion in assessing a stain: whether it can be attributed to a non-uterine source.

An important note: this siman contains many details that affect one another. Until we finish the whole siman and have all the information in hand, do not draw practical conclusions. If a question comes up, seek halachic guidance.

The sixth criterion

If a stain can be attributed to a non-uterine source, we attribute it there and the woman is not a niddah. This element of assessing stains is really an entire siman in its own right, and the details belong there.

The principle — and the logic

The principle has to be applied sensibly.

An invalid application: a woman found a large red stain on her underwear. She cannot attribute it to a nosebleed she had earlier that day.

A valid application: she had a nosebleed after putting on a white robe following a shower, and found a large red stain on the robe. She may attribute the stain to the nosebleed.

Less common today — with one exception

Finding stains on various surfaces is less common now that underwear is universal. Even so, this halachah applies often in one situation: a woman with a wound in the uterus or the vaginal area.

Dam makkah — what is it?

Bleeding that results from a wound is called dam makkah, and it does not render a woman temei'ah.

Blood originating outside the uterus, such as from the vaginal wall or the outer part of the cervix, is dam makkah.

There is a machloket about what counts as the "outside" of the cervix and what counts as the "inside."

There are even cases in which a wound in the uterus itself produces dam makkah.

What to do in practice

Invasive procedures — is that bleeding dam makkah?

Blood originating from a wound inside the uterus itself can also count as dam makkah. For example:

Bleeding caused by these procedures can often be attributed to the procedure, and the woman is not a niddah.

What to ask the doctor

A woman undergoing such a procedure should ask the doctor:

  1. What is the diameter of the instrument being inserted into the uterus?
  2. Is bleeding expected?
  3. How long is the bleeding expected to last?
  4. What is the source of the expected bleeding?

With that information in hand, she should ask a halachic question.

Further cases — fibroids and polyps

Uterine conditions such as fibroids and polyps can also count as dam makkah. A woman who knows she has a fibroid or a polyp should ask a halachic question to establish whether stains or bleeding caused by these conditions can render her temei'ah.

Expanding the sources

The source for attributing bleeding to a wound is in Masechet Niddah (66a). The Mishnah discusses a woman who is ro'eh machmat tashmish (who bleeds as a result of marital relations). It states that if such a woman has a wound, the bleeding is attributed to the wound rather than to the relations. She does not enter the status of ro'eh machmat tashmish; she is simply a woman with a wound.

A dispute among the Rishonim

The Terumah holds that she may attribute the bleeding to the wound only if she is entirely certain that her wound is of a kind that bleeds.

The Rashba holds that even without clear proof that the wound bleeds, we attribute post-relations bleeding to it. The Rashba says it is impossible for her to be certain that her wound bleeds, since she cannot visually examine that part of her body.

Most Acharonim understand the Rashba as permitting a woman to attribute such bleeding to a wound even absent proof. The Shach reads him differently: he holds that the Rashba meant she doesn't have to know the wound is bleeding now, but she does need to know that it bleeds sometimes.

The rulings of the Shulchan Aruch and the Rema

The Shulchan Aruch rules that if a woman has a wound, she attributes the bleeding to it. But if she can tell the blood of her wound apart from her menstrual blood, and it is clear to her that the present blood is not from the wound, she does not attribute it to the wound.

The Rema rules differently, distinguishing between three cases.

1. A woman with a fixed veset

She has a fixed day on which her period begins. She may attribute bleeding to the wound even if she does not know whether it bleeds.

2. A woman without a fixed veset

She has no fixed day. She may attribute bleeding to the wound only if she knows with certainty that it bleeds. The Rema qualifies this: if such a woman is in doubt about the location of the wound, she may attribute bleeding to it. If she is unsure whether the wound is in the uterus or on the vaginal wall, for instance, she may attribute.

3. Stains (rather than bleeding)

With stains specifically, the Rema says, we are lenient. Even if a woman has no fixed veset and knows where the wound is but is unsure whether it bleeds, she may attribute stains to it.

The modern complication

This halachah has grown more complex in our time, because women can now undergo a physical examination in which a doctor can see clearly whether there is a wound and whether it is bleeding. In the time of Chazal there was no visual gynecological examination.

Since we now have the ability to establish accurately whether a woman's wound bleeds, contemporary poskim are reluctant to attribute bleeding to a wound without medical confirmation.