Sharp pain during bowel movement on 1st 2 days of menses. mri shows some small volume fluid in pouch of douglas. ultrasound found no abnormalities.

You need to continue: following your GYN doctor to figure out if indeed the pain you feel during bowel movement is attributable to the MRI results - especially since the ultrasound did not find anything to cause the pains. I hope you got a transvaginal ultrasound instead of abdominal ultrasound since the former is much more sensitive to pelvic findings.