80 year old Dad due for colonoscopy & endoscopy

Hello, I’m hoping someone might have been in a similar situation or have any insight into our situation. I’ll try to keep this brief…

Our dad is 80 years old, ex smoker (smoked for over 40 years before giving up when he had a heart attack) he’s previously had Prostate cancer about 15 years ago and he had brachytherapy which was successful at the time. In the past year or so he’s had a slight increase in his PSA levels but nothing too serious and his Dr said they’d just keep an eye on it. He’s not overweight and is fairly active.
About a year ago he got diagnosed with diabetes so he’s been having 6 month blood tests and on his recent test (2 weeks ago) it was shown he was anemic. He’s never had issues with this before, so they ordered a stool sample. They rang him within a couple of days and said they found blood in the sample so they wanted him in as soon as possible for endoscopy and colonoscopy. He’s booked in for 10am this Sunday 27th September. 

He said they’ve mentioned three possible outcomes, stomach ulcer, polyps or cancer. He’s not had any other symptoms, no stomach pain or serious indigestion (no more than normal for an 80 year old) He said he’d noticed he was slightly more out of breath and tired, but I’m presuming that’s due to the anemia.

Does anyone have any similar experiences? I’m so worried but I’m trying to keep thinking clearly that there are other options other than cancer. I have read that Brachytherapy can cause bleeding even years after treatment, but I’m not sure if this is right? But I know his age and previous smoking do put him at higher risk. Thank you so much for any advice or insight.