Why would eating a soft diet eliminate the possibility of bowel cancer when it may protect the tumour from bleeding as well as the piles?

Hi so a soft diet protects everything from bleeding the gut itself any hemeroids and a cancer tumour 

I agree with the Dr its most likely constipation that caused me to fail a FOB test but why the soft diet recommendation as an eliminator?

Also whats the likelyhood I have cancer im early 40, no family history, not such a good diet lots of red meat and processed cheap stuff , I abused laxatives for about a year by mistake  which is a cancer risk, I used to have BBQs.

So stats wise whats the likelihood I have cancer roughly 

Then stats wise whats the likelihood I have survivable cancer?

So my symptoms were pink blood on a toilet tissue I stopped doing sports baseball etc and the pink spots disappeared but I still failed the FOB test twice, I was constipated both times however