I'm not aware of the rectal pain being associated with the D&C procedure, unless some of the nerves innervating the rectal area were damaged during the D&C - but this would be less likely.
You can consider a referral to a GI doc or rectal surgeon. In addition to a digital rectal exam, an endoscopy can be considered to look for any masses which may be causing your symptoms - especially in light of the difficulties in bowel movements. If the pain continues, you may want to consider a rectal biopsy.
Tough to say without examination.
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Kevin, M.D.
Medical Weblog:
kevinmd_b