@formydad Of course you are concerned, that's natural. If they do not seem to be overly concerned about the blood infection then it probably is very minor. You are confident of his doctors and the hospital, right?

The delay in a procedure like a colonoscopy can be from the infection but it can also be from many other things. Hospitals have things scheduled but often things happen to disrupt those schedules. I was supposed to have a procedure early one day when I was pre-transplant but due to a machine malfunctioning on that day my procedure got put off until the afternoon. It was annoying because I had to then spend the night in the hospital which was unplanned, but things happen.
When there is a delay I always try to think that there is a patient who needs more time than anticipated and I don't get upset because I feel if I needed extra time they would do that for me also. The only exception to that is when a doctor runs late consistently.
Try to be patient and if you can at least have contact with your dad you and he will both feel better.
Hugs, JK