The commonest difficulty with penetration is a condition called vaginimus. It is a phobic anxiety response to any attempt at vaginal penetration, in which the woman becomes anxious tension occurs in the vaginal muscles, and any attempt at penetration is painful.
Vaginismus may have followed by an unpleasant traumatic sexual event in the woman’s life but usually occurs because of ignorance or misinformation or from guilt developed from parental sexual attitudes.
Pain during intercourse may be due to other problems such as pelvic infections

5. Sexual Phobia
Vaginismus is an example of a sexual phobia, where one particular aspect of the sexual act becomes anxiety provoking. Some women show phobia avoidance of semen, and rush from the bed to have a vigorous shower whenever they come in contact with their partner’s semen.
Such phobic avoidance can totally ruin a sexual relationship.

5. Anomalous Sexual Behaviour

The prevalence of lesbianism in women is higher than in men (in Europe) and is probably tolerable due to the fact that lesbianism in women is more socially tolerable over there and it is also not illegal, the a etiology of lesbianism is obscure and there appears to be consistent adults hormonal reason for it.
Transsexualism also occurs in the women. A transsexual is convinced despite outward appearance that she is of the opposite sex. This fixed belief is usually held from childhood. The person feels comfortable if dressed in the clothes of the opposite sex and indeed may seek corrective surgery. The social pressure on the individual to conform to her outward sexual stereotype causes a great distress.

Treatment

A full assessment of sexual problem is necessary before treatment .Physical problems rarely cause of sexual difficulty.
IT CAN BE DIFFICULT TO DECIDE WHETHER SEXUAL DIFFICULTY IS CAUSING A MARITAL PROBLEM OR A MARITAL PROBLEM IS CAUSING A SEXUAL DIFFICULTY.
Obvious hostility or coldness between partners however is a poor sign in terms of a successful treatment of sexual difficulty.
Psychological methods of treatment based on behavioral principles are the most effective methods of treating sexual difficulties. Masters and Johnson’s techniques appear to be the bench mark by which other treatment options are measured. If you are worried about any of the discussed sexual disorders, see a Medical Doctor with training and interest in psycho-sexual problems.cheers