ibs, help

[Kawaii]

i have had ibs now for years ,but has gotten worse as time goes on and the older i get the worse it gets,i have has a colonoscopy,among ather test to see what my intestine are doing i was told that i have a slow colon and ibs.i have had a pulip removed from my stomick and now i have a pulip in my colon,but the dr. said its not big enough to be a problem,now just yesterday i had black stool,what in the world is going on,i am on a high fiber diet,i walk to exercize,and drink lost of water but still no relief,HELP PLEASE