Good Evening I Am 45 Years Of Age And Having

Good evening I am 45 years of age and having low pelvic pain, recently went to the ER and they said I was constipated and gave me lactulose and told me to take miralax after doing all that for a week I am now deyidrated and still have pain made an appointment with my gynecologist. My menstrual cycle last for 2 days and is dark tarry looking it doesn't seem healthy.