I have very bad "stomach issues", please help...?

This is an embarring question to ask, but I'm sure some people out there suffer from this too. I have diarrhea every day. Sometimes I can go up to 10 times per day! I rarely have constipation. It is not caused by any medication I take, it has been going on since my teens (I'm 32 now), but it never was this bad & Imodium AD always stopped it but now I can take 10 of those per day & it doesn't work. I had a colonoscopy about 5-6 years ago which showed nothing major, so the Doctor of course called it IBS. Maybe it was then but it certainly must have progressed to something more major. I don't have insurance & can't afford another colonoscopy right now. Fiber makes it worse. Does anyone know what this could be? Or if you have this, what do you do to make it better? Serious answers only please.