Hi, Thanks for writing in. Cancer in rectum stage 4 requires regular follow up and treatment. It is important to know if he is having any complication from surgery for cancer and whether there is any problem with bypass. Since this is stage 4 cancer the survival is till 2 years and it is important to start chemotherapy early. If blood reports are normal and his general condition is good then starting chemotherapy might be required to extend his survival. Chemotherapy is given in cycle and blood report to be repeated regularly. Treatment response is known by doing follow up test. Please do not worry.