pills contain derivatives of progesterone and estrogen, hormones that have thousands of effects in the body, most them we probably don't understand fully. In the case of constipation, few women in controlled settings report more regular bowels. Its true that some women will report to me that the bill did this or that for them and I believe them, but its not consistent enough of a finding for the pharmacology world to decide that they can treat constipation. If you look on the internet, you will find women claiming that the birth control pill CAUSED constipation in them. In conclusion, I wouldn't plan on it having any effect on you bowels (other than a slight higher risk of gall stones). The other two effects you mentioned have been documented. The pill can treat certain kinds of refractory acne
. Oral contraceptives also increase your risk very slightly for breast cancer while reducing the risk for ovarian and uterine cancers. Hormonal contraceptives cary risks and benefits in many aspects of your life. It is important that you discuss each of these with your primary care physician
or OBGYN, whoever you see for you feminine health. He or she can give you the best advice on which mode of protection is best for you. Good luck.