can cause a number of problem including brusies, scar, pain, swelling, fluid imbalance , thromboembolism
and fat embolism
and in your case there is chance of acquiring bacterian infection because from long time you are on steroid
and your general physicsl condition is also not well and there is a chance that your CS may flare up because it is already inflammed and so it can acquire infection quite easily due to the procedure if complete sterilisation is not maintained during the procedure.
i would suggest you to not to go for this now but you should rather consult an immunologist for better management of your cystitis
as taking steroid for long time itself has a lot of side effects.
wish you all the best.