The possible causes of common stool bleeding are: external hemorrhoids, internal hemorrhoids, adenomas, colonic ulcers, malignant tumors, liver disease portal hypertension to rectal veins from dilation, rupture. External hemorrhoids and internal hemorrhoids are mostly fresh blood, dripping in small amounts before stool or wrapped in feces, and external hemorrhoids may be accompanied by pain; adenomas and colonic ulcers may have blood clots and fresh blood after stool depending on the location, and are mostly painless; malignant tumors have variable bleeding, but mostly have more frequent, unformed stools and mixed with pus and mucus stools; bleeding from portal hypertension to dilated and ruptured rectal veins in liver disease is often associated with impaired liver function and coagulation mechanisms. The bleeding is persistent and large in volume.