Hello, I would be happy to help you with your question.
Consider that given you have been diagnosed with IC, your urologist
might not be taking into consideration issues in the vaginal area. Yes, you might have something like a yeast infection, but it does not exactly fit with the exacerbating symptoms of movement, walking, and sitting - and improvement after you urinate. These symptoms also do not necessarily fit with an IC flare. I would consider a second opinion
with an OB/GYN before going through with hydrodistension. Also consider antihistamine medications for treatment of the possible IC flare.
I hope that this helps and good luck!