Crohn’s disease, diverticulitis, infection in kidney, kidney stones, constipation, ovary involvement in women, ectopic pregnancy in women, mesentry involvement, and an abscess in rectus abdominis muscle or psoas muscle can all cause
lower right abdomen
pain.
Right flank
pain is generally due to kidney stones. All the conditions mentioned above can cause pain near the hip area on the abdominal side.
An ultrasound or CT scan of abdomen is definitely required.
Hope this helps.