I had a Botox shot approximately 10 yrs. Ago with no anesthesia in my urologists office. The needle was about 12 inches long. It was one of the worst procedures ever. I hadn't been diagnosed with interstitial cystitis yet and I had no relief at all from the procedure. I too have urine retention. Long story short and 2 urologists later. I was finally diagnosed with interstitial cystitis and for several months I would have infusions directly to my bladder several times a month. After awhile they took became ineffective so I went to the hospitals pain clinic and started on lyrica. Lyrica helps tremendously and I no longer have pain in my bladder that would have me doubled over with my heating pad as my only relief. Of course the lyrica has side effects too so I had to chose whether it was worth taking it. You take every day and not just on demand. I still have the problem of retaining urine so I have to double pee. Meaning that I urinate and then go back after 5 mins. Or so and pee again. Getting the IC diagnosis was key to getting relief so my advice is make sure that your urologist is ruling that out. It took me several urologists and 10 yrs to get mine but it was worth finally getting the relief