Hi and welcome to HCM!
Thanks for posting your query here.
The pain is of renal colic- a stone in the urinary tract
. A stone can be in the pathway from the kidney to renal pelvis
to urinary bladder
and to the exit. At that time may be you are having a small renal stone of less than 3 mm which has passed out in the urine. A stone while passing in the tract may cause a injury to the inner layers and cause a bleeding. This gives the RBC or blood cells in the urine. When the stone is passed out the injury get healed and there are no more RBC. Please undergo a scan or an x-ray KUB to find out any remaining stones. Take plenty of water to avoid stone formation.
Hope this is helpful to you.