I would echo the advice of the previous postings. Rectal bleeding is never normal and should always be medically investigated. Google/Yahoo "rectal bleeding" so that you are better informed of all possibilities when you discuss with your doctor - who should be a GI specialist rather than a GP. I would suggest insisting on a colonoscopy if there is any ambiguity in the diagnosis (" well it looks as if it might be .....").
28 is very young for colon cancer - but there have been postings on Medhelp where, exceptionally, it has been detected at age ~20 so, I would suggest, that you would be well advised to get to the bottom of this now. If you do not, then I fear that worry will eventually drive you to what is logical.
Good luck
Morecambe
It may just be hemorrhoids, but any time there is that much blood, you need to get it checked out! Especially with colon cancer in the family. Early diagnosis may save you lots of huge bills in the future, spend the money and get checked out ASAP.
I would go to a free medical clinic asap