So sorry to hear about her multiple medical problems. It can be very difficult to understand what is normal and what is something that requires medical attention for any parent, and parents of children who have been through so much are even more concerned--if that is possible. While colon cancer can be one cause of rectal bleeding
and blood in the stools, it is not the most likely cause of rectal bleeding in most 19 year old females. Obviously, there may be special circumstances for your daughter that I am not aware of, and that is why you should discuss this with your doctor
. He or she would be able to do a physical exam and determine if there is any obvious explanation for what is happening. One very common cause of blood in the stools and on the tissue paper after wiping is hemorrhoids
, which can be common even in young people such as your daughter. It is something that is readily diagnosed, and sometimes does not require further testing. Your doctor may be able to make some recommendations that can help her to feel better, and if it is not hemorrhoids may be able to recommend further testing. Please speak with your doctor.