First and foremost I would recommend getting a second opinion. Perhaps a naturopath.
I went to an MD doctor about, erm, bowel issues. She prescribed the fiber stuff to take daily. Ick. I'm not sure whether or not it worked because I quit taking it after about a week. I went and got a second opinion from another clinic (an RNP, actually) and she recommended I go to the store and buy probiotics. The probiotics worked for me, and I take them whenever I start getting these "issues." They are also cheaper than the fiber crud. I would try other options before succumbing to the prescription--remember, doctors are sales persons for pharma--they do honestly try to help you, but typically recommend medication as the first solution. I would recommend to get a second opinion, but also just go to the store and try buying some probiotics. It makes sense because changes in bacteria change your stools. Every time I get on antibiotics I see this happening, and the probiotics change it too.
Stumbled into Primal due to food allergies, and subsequent elimination of non-primal foods.
Start Gluten-Free/Soy-Free: December 2012; start weight 158lbs, Ladies size 6
Start Primal: March 2013, start weight 150lbs, Ladies size 6
Current: 132lbs, Ladies size 2
26lbs lost since cutting the crap.