Left very lower stomach pain. Scared?

I am a breastfeeding mom, I am having very  lower left side stomach pain near to upper thigh I don't exactly that location part name ,but I am facing these since from 3 years it started when I delivered my first baby,it will come and gone often and ofte n, before starting second pregnancy again I got that pain ,I thought it's may be due to kidney stone then its disappear but now from past 4 days again I am facing that pain ultrasound shows normal only I have kidney stones that is in the midpole of the kidney not in urethra, doctor said thatI am having rectal prolapse and utreas prolapse I don't know why I am facing these pain sometimes it's very sharp pain and that pain increase with my movements and if I stand so long , another one doctor suggested me to Doppler scan ,what shall I do ? And from past 3 months I have less appetite ,and sometimes constipation and sometimes diarrhoea I am very scared? And I have 2 polyps in anal area that too scaring me it's created health anxiety too