What Causes Bulge Between Vagina And Anus Hole?

I recently had a vaginal cuff repair (emergency surgery on July 29th) due to a hysterectomy I had back in May. My heeling process has been very slow and I recently went to a specialist who saw I had an infection. I am on day 5 of antibiotics and the pressure has gotten better but not gone. Now I have noticed a bulge in the area between my vagina and anus hole. Its not painful but my vagina still looks very open and when I push on the bump it closes my vagina. I think something could be pushing against the back wall of my vagina? What could this be?