What Is The Rectal Bleeding After Starting Adderal?

Five days after beginning taking adderall, I have developed rectal bleeding. However, last weekend I also walked 7 miles in two days with a time of 1 hour 45 min. on each of those days. Trying to determine if the strenuous walk caused the problem or made the problem worse. The bleeding has lessened but is still present as is some discomfort.