Marion Sims discovered a condition called "vaginismus", in which a
woman felt such pain from intercourse she was unable to bear
penetration. He prescribed surgery, but another treatment was to put
the woman under anesthesia so her husband was able to have sex with
her. Sims described one case in which a physician had to visit the
couple two or three times a week to anesthetize the woman before love
making.
   -- American Women, 400 years of dolls, drudges, and heroines. Gail Collins.