A uterine biopsy, or endometrial biopsy, often causes cramping pain, and many doctors recommend taking a pain reliever 30 minutes to an hour before the biopsy, says WebMD. One reason for the pain is lidocain spray, which can burn, and another reason is the clamp on the cervix, states Wikipedia.
The uterine biopsy procedure itself also causes pain because a doctor retrieves a piece of uterine lining with a tube, explains Wikipedia.
Cramping may be sharp and similar to severe menstrual cramps when the speculum is moved through the cervix, and when the sample is gathered, says WebMD. Some women experience vasovagal reactions, feeling dizziness and nausea. Vaginal bleeding is common, and a pad helps.