The HSG images show uterus bicornis bicollis with mildly dilated right fallopian tube. Left horn is not completely filled. Left fallopian tube is not seen – ? rudimentary horn.
The fistulogram is very confusing. I think there is a communication of the fistula with the left horn and the rectum. Only frontal views have been shown. An oblique or lateral view would be ideal to show the communication between the subcutaneous fistula, the Uterus and the rectum.
Do you have a lateral or oblique image to show?

Ok George, Now I’m going to go all out…. and Guess

First things first…

Does this lady have endometriosis?
What was the previous surgery, Cesarian section or something else (to do with endometriosis, maybe)?!

Is the dome like contrast-filled thing in the 2nd picture, the bladder? So is it a cutaneous-vesico-utero-rectal fistula

I would like to revise my finding on HSG to Uterus Didelphis, you have cannulated one cervical canal, the contrast is leaking out through the other canal on the right into the vagina.

The large blotchy contrast filled areas overlapping everything else in the fistulogram are likely to be sinuses in the subcutaneous or parietal muscular planes.

You could have done a CT (plain) after the fistulogram, it would have shown you the anatomical findings better.

Don’t keep us waiting too long for the answer. The suspense is killing me