Hello. Welcome to hcm.
Chrons disease is a pathology of small intestine
mainly where there will be destruction of mucosa. Causes are varied. As the inflammation progresses,it starts eroding and punctures the intestine.
You were operated upon n that part of intestine might have been removed. But inflammation will not stop. So here,it has eroded the intestine and eroded the uterus
also. So gas n bllod produced in intestine is coming from your vagina.
I advice you to see your doctor,who wil operate for your fistula and you will be cured of your symptoms soon. There is no drugs to cure fistula except surgery.
All the best