I was in your situation over the summer. I has rectal bleeding for weeks (eventually months) on end, along with some itching and also had some other concerning symptoms like weight loss, occasional loose stools and a couple of weeks with such bad trapped wind that it woke me at least once. I also had thyroid cancer a couple of years ago, so again, the whole "yeah, it's unlikely but so was that and that turned out to be the case" was playing on my mind. 

My family also thought I was being dramatic.

I was sent to see a specialist and he said that at our age and with those symptoms, the odds of it being bowel cancer was less than 1%. I asked him before he said that how worried I should be and he replied "zero. Not at all." He did do a colonoscopy just to be certain and all he found was a couple of piles. I am sure it is the same in your case, especially as it sounds like you have less symptoms than I do. I know this is limited reassurance though.

Thank you ever so much for taking the time to reply to me. 
 

As you say it was unlikely to be cancer the first time, yet it still happened! I think my chances of getting breast cancer at 35 were 0.5%, I was messed about by my GP as well and had to keep going back.

I think once you've had cancer you've lost that 'peace of mind' that it's likely everything is ok.  
 
I will try and remain positive, I do have the symptoms of a pile and no change in bowel habit, etc.  I don't think I could cope with another cancer diagnosis!!

Given that you have symptoms of piles and no changes in bowel habits, I would say it is highly unlikely to be anything other than piles. My concern was that I had some symptoms like weight loss that could not have been caused by piles (though I do suspect that was due to the removal of my thyroid, as weight changes are part of thyroid issues).

I do know though how hard it is to write something off with "well, it's a thousand to one against it," when the slight chance already came up. 

While my doctors did take my thyroid seriously, they were very much, "oh, it's highly unlikely to be anything serious, but we just have to check, but personally, I don't think there is anything at all wrong."

Everybody kept telling me "well, you are not going to get the unlikely option twice in two years. You'd probably make national news if you got bowel cancer at 40, two years after thyroid cancer." But that isn't much reassurance because one thing has really no effect on the other.

So I've been to see my GP face to face today and she's diagnosed internal piles after an examination.

Ive got myself into such a state over this, I don't know if I trust her assessment!