This is something I've learned only recently. There are two types of fibers from foods: soluble and insoluble. If fibers help you, then I recommend sticking to soluble fiber foods. Insoluble fibers can worsen the diarrhea symptoms.
Basically, soluble fibers absorb water/liquid in the intestine while insoluble fibers won't. Green vegetables are almost all insoluble fibers. Grains like wheat, brown rice, oats, are mostly soluble fibers that absorb water in your intestine, so they should help to reduce diarrhea.
I had my gallbladder removed 12 weeks ago. I've been suffering from chronic diarrhea from day one after the surgery. Though the severity has decreased somewhat, I still suffer from it.
I've been on a strict, ultra lean diet from day one. Unlike what my doctor told me, everything I eat gives me diarrhea, just that some foods will reduce the effect, while others will worsen it.
I have found the worst offenders are coffee and green vegetables. Oddly, though barley and flax seed are mostly soluble fibers, they go straight through my digestive system and worsen the diarrhea.
What works best for me are pastas and grilled chicken. The pastas with iron supplement added seem to work best for my digestive tract in reducing diarrhea symptoms. Grilled chicken also helps.
I think everyone reacts to foods differently after gallbladder removal. Some experience no diarrhea symptoms, while those like me suffer quite extensively.
What I find helpful is selected few soluble fiber foods and grilled chicken. Rice and oats seem neutral to my system, so I eat them as I want. Though 12th week onward from surgery, I find that I am still unable to handle fatty/greasy foods and green vegetables, and particularly coffee and milk.
I have tried digestive enzymes, probiotics, and vitamin B complex. None of them helps, so for now I'm sticking to what helps my system and avoiding what worsens the effect of diarrhea.
I am holding back from getting a prescription medication for now. However, if the dreaded symptom persists with no sign of improvement through healing and recovery with a healthy diet, I may resort to either Welchol or Questran.
Hope this helps, and good luck to your recovery.