The possibilitys are that after
biopsy, he did not cauterize the area properly, he perforated an adjacent area
with the tools used for biopsy or something not of his fault. Did he find signs of diverticulosis, (a deepening of the tissue between the "ribs" of the intestine resulting in the effect of the intestine appearing like a flexible pool hose as opposed to being smooth inside) or hemaroids?