I feel the same way if I'm not on a medication like Zelnorm or Miralax. Fiber alone just doesn't do enough for me. Right now I'm taking Miralax daily. Have you ever tried it? You do have to get a prescription for it.
ps I used to drink coffee too (still do on occasion). It would sometimes make me have a bm, but usually didn't. Now that I've been on Heather's diet, I notice that I tend to get a tummy ache after drinking coffee (but no bm).