I would have liked to know your age and what cancer did your father and grandparents die from. Certain types of cancers of the colon
do have a hereditary component and the risk is further compounded by alcohol abuse
and poor dietary habits. The good news is that the type of bleeding you have described is most commonly due to hemorrhoids particularly in the young age group. However, there is only one way to find out whether you have cancer or not and that is to show it a surgeon or cancer surgeon who will examine your anus and rectum in the opd and remove your dilemma.