Sorry about your brother, its been 14 months since my wife died of pancreatic cancer,as for colonoscopy do it! My prostate was enlarged,and eventually caused my bladder to quit working, if I had had the surgery a year earlier, all might have gone well, dont take chances, while my predicament isn't fatal, yet, the treatment is cumbersome,and sometimes uncomfortable, but heck 72 is a age that most guys never reached before.