One thing that has really helped me is making a smoothie every morning with 2 tablespoons of ground flax seed. I use yogurt & fruits with it & it tastes great. I have been doing this about 15 years now. I am in trouble if I don't use this, really makes a difference.

My GI Dr recommended Citrucel fiber because it's less likely to produce excess gas. I found this info online: The cellulose in Citrucel is a non-fermentable fiber, which means that the bacteria in your digestive tract doesn't ferment it. If your digestive tract doesn't ferment the fiber, you're less likely to experience gas, bloating and other gastrointestinal issues...Wheat dextrin (as in Benefiber) is a fermentable fiber. This means that you might experience more gas and bloating, but fermentable fiber can also help increase mineral absorption and decreased production of certain kinds of bad bacteria, according to a 2010 article published in the "Journal of Medicinal Foods."