I'm a little concerned when you say that the ultrasound didn't reveal anything??? Did you have a HIDA scan done? Is your doctor saying you have gallstones or a non-functioning gallbladder?
I had a HIDA scan that revealed a non-functioning gallbladder in 2011. Fatty greasy foods, raw veggies, (but not raw fruit!) milk, spaghetti sauce and most tomato based foods caused pain in my chest and referred to my back. It took doctor's 2 years to figure out to do an Ultrasound/HIDA scan!
Swimmer88, Welchol would have cost me $300 if I did not have good insurance!!
Ask your doctor, but my doctor said to try adding Citrucel or Metamucil to my diet to help with the diarrhea; I could not take Welchol made me have constipation problems. Also, eating plain organic low fat yogurt helped a lot. Coffee, tomato sauces, fatty, fried foods and even salad was out of the question for the longest time until I tried adding the Citrucel and yogurt. Others have had good luck with calcium pills.