Bad genes. Genetic predisposition, chronic constipation, chronic obstructive pulmonary disease (coughing), asthma, diabetes mellitus and multiple childbirths can lead to rectocele. I am not aware of any studies to suggest that anal intercourse is a risk factor.
Please let me know if there is anything that can cause a woman to have a rectocele besides child birth or excesive anal sex?
Rectocele. Chronic constipation or inflammatory bowel disease are also causes of rectoceles in your age group. It is important to have a complete physical exam, including a good rectal exam. Increase both the amount of fiber and fluids you consume, as even if this is not the cause of your problem, it will certainly help symptomatically.