 [ Symptoms ] what may cause blood in the stool  more importantly what may cause a lot of bright red blood in the toilet after bowel movement and a rather large blood clot i had to remove myself from the toilet to clean myself and found the blood clot about the size of a small chicken liver and almost the same consistency no more bleeding since bleeding i have experienced before and does not concern me but the clot was rather scarey [ Disease ] the source will need to be found so you will need to see a medical provider for an examination it could be a fissure a tiny tear in the anal area a hemorrhoid internal or external a polyp or