Hysterosalpingogram (HSG)An HSG is a hysterosalpingogram, an x-ray of the interior space of the uterus and fallopian tubes using a contrast dye. It can be used to look for uterine abnormalities and adhesions, determine how much infringement fibroids are making into the interior of the uterus (to some degree), and identify if your tubes are open (referred to by docs as "patent"). Some docs do it standard a few months after a myomectomy, mine did not. The dye does have what my RE referred to as a "voodoo effect", where there is some slight increase in pregnancies after the procedure, speculated to be caused by the dye perhaps causing the little hairs (cilia) in the tubes to function better.
It can be done by your doctor in a radiology facility or by a radiologist -- mine was done by my RE and she was a lot more comfortable with the procedure than the radiologist I could tell.
They insert a catheter to insert the contrast dye through your cervix; a good cough evidently will open up the cervix so it is less painful. The dye feels like pressure going in, and it can cause a drop in blood pressure. It's generally uncomfortable and causes some cramping. My RE tried to manipulate my uterus for the xray shots using the special speculum and I found that to be very uncomfortable with my 6-7cm (at the time) fibroid.
Here is an link detailing Guidelines for the Performance of HSG - it advises taking 1000 mg of NSAIDs prior to the procedure.
Rarely it can cause infection, and some people are allergic to the contrast medium. Some docs give antibiotics preventatively ahead of time, they also might have you take a heavy dose of Tylenol an hour beforehand.
Here are some links to sites showing images from HSGs:
HSG Link 1
HSG Link 2
HSG Link 3
I should go pick up my x-ray film from the University of Washington Radiology Department, where I brought it when I consulted about UAE a couple years ago. I'd like to scan it and and post it here so you can see what my distorted uterus looked like.