A woman who sees blood on account of relations — she becomes a נדה, and, if it recurs three times, the concern that it comes from the מקור (forbidden to this husband); distinguishing the מקור from a מכה / the צדדין; the בדיקת שפופרת of old and today's medical diagnosis; the ne'emanut « מכה יש לי »; the Rama's leniency, « אין אנו נוהגין להוציאה » (Shulchan Aruch, Yoreh De'ah 187 — 14 se'ifim). A matter both halachic and medical: referral to the Rav and to the physician.
אִשָּׁה שֶׁרָאֲתָה דָּם מֵחֲמַת תַּשְׁמִישׁ — מְשַׁמֶּשֶׁת שָׁלֹשׁ פְּעָמִים וְרוֹאָה, וְאַחַר כָּךְ אֲסוּרָה לְשַׁמֵּשׁ עִם בַּעְלָהּ זֶה, מִפְּנֵי הַחֲשָׁשׁ שֶׁמָּא הַדָּם בָּא מִן הַמָּקוֹר. הגה: וְיֵשׁ אוֹמְרִים שֶׁאֵין אָנוּ נוֹהֲגִין עַכְשָׁו לְהוֹצִיאָהּ.
A woman who saw blood on account of relations (מחמת תשמיש) — after it occurred three times, she becomes forbidden to this husband, out of concern that this blood comes from the מקור (the uterine source). Rama's gloss: some hold that it is no longer our custom to force the divorce (אין אנו נוהגין עכשיו להוציאהּ).
Shulchan Aruch, Yoreh De'ah 187:1 (excerpt, with the Rama's gloss)LEVEL 01
Hebrew text of the 14 se'ifim with a fluent English translation. The woman who is רואה מחמת תשמיש (forbidden to this husband after three times), the distinction מקור / מכה / צדדין, the בדיקת שפופרת and today's medical diagnosis, the ne'emanut « מכה יש לי » and the Rama's leniency — set out with dignity and sobriety, with practical cases referring to the Rav and the physician.
📖 StudyLEVEL 02
In-depth pilpul: מקור vs צדדין / מכה, the heart of the siman; the mechanics of the בדיקת שפופרת (Taz sk5, שיעור אבר בינוני); what may be attributed (a וסת, a מכה) and the Rama's ספק ספיקא reasoning (se'if 5); the ne'emanut « מכה יש לי » (se'if 6); the חזקת ג׳ פעמים and the sequence of husbands (« אין כל האצבעות שוות », Taz); the Noda BiYehuda's nuances (PT — a later וסת קבוע, שפע דם, עיבור / הנקה).
📖 StudyLEVEL 03
Comparative tables (מקור / מכה / צדדין, what may be attributed, with or without a וסת קבוע and the ספק ספיקא, the ne'emanut), golden rules, classic pitfalls and cross-references (sim. קפ״ד, קפ״ו, קפ״ח, ק״צ, קצ״ו); memorization of the 14 se'ifim of ro'ah machmat tashmish.
📖 StudyLEVEL 04
Two parts: the approach of Chabad and the shitah of the Tzemach Tzedek (Daat HaRav, in principle), then the halacha lema'asse of the other poskim — Beit Yosef, Rama (« אין אנו נוהגין להוציאה »), Shach, Sidrei Tahara, Chochmat Adam, Aruch haShulchan, Noda BiYehuda, Taharat haBayit, Shevet haLevi, Nishmat Avraham (the medical angle) — always referring to the Rav and to the physician.
📖 StudyThe siman addresses, with gravity, the woman who sees blood on account of relations (רואה מחמת תשמיש). Two things are bound up in it: on one hand she becomes a נדה; on the other, if it recurs three times in a row, a concern arises that this blood comes from the מקור (the uterine source), which would render her forbidden to this husband (Shulchan Aruch 187:1). The whole concern is therefore to determine the source: if the blood is from the מקור, there is a prohibition; if from a מכה (a wound) or the צדדין (the walls), it does not carry that prohibition. It is precisely this distinction that, most often, allows one to be lenient. Such a case is never decided alone: it calls for an imperative referral to your Rav and to a competent physician.
The Shulchan Aruch (187:2) describes the בדיקת שפופרת: a tube (שפופרת) holding a מכחול wrapped in מוך, inserted to where relations reach; if blood is found at its end, it is attributed to the מקור and she is forbidden; if not, it is attributed to the צדדין and she is permitted. This is the forerunner of an approach that remains valid in principle: establishing where the blood comes from. Today this diagnosis belongs to medicine: a physician (gynecologist) looks for a cause at the cervix or the walls — a polyp, an ectropion, a micro-lesion — that is, a מכה / צדדין rather than the מקור, whence, often, the leniency. Never by self-diagnosis: the source is determined with a physician, and the halachah that follows, with your Rav.
Upon the older principle — three bleedings in a row obliging the woman to part from this husband — the Rama rules: « יש אומרים שאין אנו נוהגין להוציאה » — it is no longer the custom to force the divorce. The practical path then runs through the diagnosis of the source and the couple's guidance by a Rav. Moreover, the Shulchan Aruch (187:6) recognizes the woman's ne'emanut: if she says « מכה יש לי » (I have a wound there) or « ברי לי » (I am certain this blood is not from the מקור), she is believed and remains טהורה. These leniencies are real, yet they apply within a framework: their application is decided with your Rav, after the source has been clarified by a physician.