What kind of diarrhea do you have? Is it just water, constant loose stools without water or is there bile (yellow and burns)? I have had good success with two things: calcium and Welchol. The Welchol is only for bile diarrhea, and if you haven't had you gall bladder taken out, your doctor may not give it to you. Bile diarrhea is a sign of a bad gall bladder, but even after you have it out, you can continue to have the D. But a lot of G.I.'s are getting wise to the fact that Welchol--which is normally a cholesterol medicine--soaks up the excess bile and stops the D.
The calcium is really good for the other types of diarrhea. I developed D last summer that was separate from my usual bile problem. I had constant loose stools but no water. I started out taking two calcium pills a day (generic Caltrate 600 w/ Vitamin D) in addition to my Welchol and that straightened me back up.
I notice in your signature line that you have acid reflux. Did you read my post (it has a yellow caution sign beside it) on heartburn meds? Also read the one on C. difficile. Certain heartburn meds make you much more likely to catch the bad bacteria known as C. difficile, which causes pain, bloating, gas and lots of D. They can determine if you have it by testing a stool sample. If you have it, they can treat it with antibiotics and probitics together.