For anyone wondering if it's possible to have a high FIT test and end up not having anything serious, the answer is yes.
I had a positive FIT test of over 400ug/g in April. My symptoms were rectal bleeding, diarrhoea and some tummy pain. My GP said there were no signs of piles or anything abnormal in my rectal exam.
I recently dropped from 7st 6ibs to 5st 11ibs in the space of a few weeks. I was referred for a sigmoidoscopy and have in fact got internal piles.
I'm waiting for biopsy results so hopefully they'll be normal aswell.