rice, potatoes, pasta can have a binding effect on my stools not always but sometimes.
the most formed stools I ever had consistently was when for the first probably 18 years or so I religiously took some Metamucil powder mixed with juice in the morning. only the morning. they now have Wafers and on other posts here people talk about having a wafer before each meal. the pills didn't seem to work for me as they would fly through my guts and not have time to break down and absorb water.
I think they now make sugar free Metamucil, not sure about the wafers. I have never had them. some people also like to just go buy plain psyllium husk from the vitamin store. its probably cheaper and has less additives than Metamucil.