Hi jp77,
Welcome to Healing Well
I don't know for sure but I would think that you wouldn't have to worry about the amount of sorbitol in your toothpaste and mouthwash since you are not swallowing it even with the small amount that you do inadvertantly or the amount that absorbs into your bloodstream. You may want to switch toothpastes for a while to see if it makes a difference. Do you keep a food diary as well to record all the ingredients that you are injesting in your food. This is a really good way to identify your trigger foods/ingredients. I'm glad you have gotten some good advice from the forum that has helped you. Please continue to post and welcome to the IBS forum.
Take Care