Hi ! Was your appendix removed during the hysterectomy
or not ? If not, a mild attack of recurrent appendicitis
cannot be ruled out which can be diagnosed clinically only by examination by the treating doctor during the pain.
It could also be due to a small ureteric stone with hydronephrosis
due to back pressure and can be diagnosed by a repeat ultrasound
with special reference made to the KUB.
Next possibility can be some adhesions in the bowel and the scar.
A small cyst in the right ovary could only be an incidental finding or the ovary might be getting twisted intermittently along with the cyst.
One can go for a CECT after showing it to the treating gynaecologist/surgeon, and if it is troubling more, then a diagnostic laparoscopy
is an option.
Wishing you an early recovery.