Hi Belinda! I am so sorry you had to go through all this, but thrilled that you sailed through it and are doing well. That is fantastic!
I unfortunately do not have any referrals for dietitians in this area. I would ask your surgeon, general GI doc, and even regular family doc.
Reduced bile usually means reduced ability to digest fats, which is already kind of an issue with IBS. Go low fat, even very low fat, just not fat free. Peppermint can stimulate the production of bile, so you may add in peppermint tea and/or peppermint oil caps and see if those help. They will help with IBS as well.