During the delivery, episiotomy extends through the sphincter of the rectum, but the rectal mucosa is intact. How would you classify this type of perineal tear?

A first-degree tear involves the vaginal mucosa or perineal skin, but not the underlying tissue. In a second degree episiotomy, the underlying subcutaneous tissue is also involved, but not the rectal sphincter or rectal mucosa. In a third degree tear, the rectal sphincter is affected. A fouh-degree episiotomy involves a tear that extends into the rectal mucosa.