Niddah 22: Discharging Items that Might Render a Woman Ritually Impure

Yesterday's Mishna noted that if a woman discharges a number of things that are red - things in the shape of shells, or hairs, for example - she is ritually impure if they are indeed blood.  Today's daf clarifies how this was done.  A woman would ask her rabbi about the discharged items. The rabbis would suggest that she put them in water to see if they dissolve.  If so, they are blood and she is deemed ritually impure.  If they remain intact, a doctor is consulted.  

Two examples are provided.  Rabbi Elazar ben Rabbi Tzadok told stories of his father being asked for advice.  If the rabbis of Yavne did not know the answer, a doctor would be consulted.  The doctor explained that items that look like red hairs are actually from a mole within a woman's uterus that released hairs.

These stories are still used to prove that experts can be consulted, even by rabbis, when the rabbis do not have full knowledge of a subject.  One of the great measures of Judaism is its capacity to hold many opinions.  Even more, when showing humility, the great rabbis teach us to listen, not only to preach about what we think we understand.