Once full dilation is reached (about 10 cm), the third phase of labor begins, the one called expulsive, in which the fetus is born.

While during the dilating phase the woman had to try to work with the contractions without resisting them, in the expulsive phase the voluntary contractions of the abdominal muscles (voluntary striated muscle) play an important role in helping the uterine muscles expel the fetus.

During the expulsive phase the woman is asked to "push", and the midwife, to explain how she should do this, often uses the phrase "as if you were having a bowel movement".

While on one hand this clarifies for her what she has to do, on the other it can trigger in her a strong, deep fear that can have an inhibiting effect on the expulsion, or that can make her "lose her head" to the point of no longer being able to coordinate her breathing with the contractions, resulting in her feeling much more pain.

For many women, in fact, this request brings back to the surface difficulties experienced during a particularly conflictual period of their childhood.

It puts them, that is, in feedback with the desires and fears experienced during the second and third year of life, during what is called the anal stage. This is the period of toilet training, in which the mother's demand for control over one's own sphincters clashes with the desire to hold in or expel the products of one's own body when and where one wants. Believing they will reach the goal more easily, many mothers conceal an emotional blackmail behind this demand: comply in order to be loved, as opposed to following one's own desires and risking the loss of maternal affection.

Depending on one's own experiences, it can therefore feel unacceptable to do something that may lead to defecating "on request", in front of whoever is assisting with the birth, just as it can feel unacceptable to have the possibility of soiling one's own baby with feces.

In order to reduce inappropriate, traumatic tearing of the pelvic floor during the passage of the fetus, an episiotomy can be performed. This is a small longitudinal cut, of limited size, extending toward the rectum, or a transverse one, larger, extending laterally. In this latter case it creates more space for the passage of the fetus but causes greater damage to the later functioning of the pelvic floor because of the resulting scar.

An episiotomy can arouse intense fear in a woman, because it reactivates castration anxieties unconsciously experienced during a phase of her childhood. The inevitable comparison with the male, endowed with a penis, had stimulated the little girl's fantasy of having possessed one and having lost it as a punishment inflicted on her. The expulsive phase of childbirth, in which the woman "loses" a part of herself (the baby) and often undergoes a cut to her genitals, makes these fantasies current again, and puts her in direct feedback with the anguish that may have accompanied them.