mucus, blood in stool

I am 59 with family history of colon cancer (mother,brother) .  I have had colonoscopies with polips(sp)all okay. Now have right flank pain, constant movement of bowels with mucus and blood-had hemmoroids (hemorrhoids) removed(which never caused me a problem) thinking the blood may be the hemmorids again but the constant bathroom thing and mucus has me worried - I was also diagnosed with barretts disease and bleeding ulcers but am told the ulcers are healed - as far as the barretts - dr. doesnt seem concerned - this is making my life horrible - i have to carry a bag with extra clothes and know every bathroom on my ususal route- I am going at least 8 x  a day and  i feel nauseated, and also always feel like i still have to go; even with finished - i know this is quite nasty but the mucus has started several months ago along with very small and loose stools and sometimes leakage.  Don't know what to think - The dr. I saw ruled out ibs,crohns and parrasites - so now what could this be???? HElp