The odds are you haven't all that much to worry about. I am twice your age and about two years ago, I had blood when wiping almost daily for a couple of months, along with weight loss, occasional loose stools (maybe once a week) and trapped wind. The specialist said that as I was only 40, the odds of it being cancer were "less than 1%" and I would be "the unluckiest person in the world" if it turned out to be.

It turned out to be hemorrhoids, as we all suspected, probably combined with thyroid medication and possibly the stress of the whole situation.

Lots of things can cause bleeding. Hemorrhoids and a fissure would be the most common. Constipation can also cause it and this seems probable in your case, as you said it didn't happen when you took laxatives.

It sounds like they might be slightly concerned about IBD because of the raised calprotctin and want to double check to rule it out.

I have been in your shoes and at the moment it feels very real. My GP advised if the blood is fresh then it's very unlikely to be something sinister. If the blood is old and therefore black then it's time to worry.

Just after I had my son mine turned black and I cried in the hospital, turned out even then it was just the iron tablets they had given me.

I hope this helps in some way