Ob-Gyn questions? Ask a gynecologist online.
generally, unilateral pain like this could be caused by an ovarian cyst, but this should have been detected by the ultrasound examination. So the reason for your pain really can be an intestinal problem like inflammation or adenoids. Therefore I would recommend a colonoscopy to get a secure diagnosis. As you mentioned that period stay away because of the iud, I suppose thst it´s a hormone spiral. This can cause such problems sometimes as well, so if the intestinal examination should come out without a result, a change of the contraceptive method could make sense.
Hope you get well soon, kind regards,
Dr. N. Scheufele
if there are still open questions, I will be glad to answer them. Otherwise please don´t forget to honour my work with a kindly rating (3-5 stars).Thanks a lot, all the best for you,Dr. N. Scheufele