I had Cystitis on Christmas Day and could not get anti biotics until later in the week.  I took a course but because of the timing my sample was not sent to the hospital and the cystitis came back and was really bad.  I took a second course of antibiotics and the Cystitis has gone but I have tenderness across my abdomen.
Hi and welcome to Chat Doctor. Thank you for your query. Yes, such tenderness may be sign of prolonged cystitis, and it should be better within 4 weeks of treatment. If not then it would be good to do cystoscopy and pelvic Ct scan since some other issues may persist such as ovarian cyst or MoMA of the uterus. In every case it should be treated with fluids intake raspberry tea and antibiotics. I hope I have answered you query. Kindly regards. Wish you a good health.