Rice gets mine too.
Try Oatmeal. We chop dried fruit into it like prunes, rasins, or such. Her fav is (1) tropical mix with mangos and papays (2) some mix with apples and cherries and rasins. Oatmeal can be ground in the processor to a powder if the finer texture is needed.
Fresh fruit helps alot and make them drink. We got much better regularity from ours when we started with the yogurt with active cultures and probiotics. We also use a supplement with digestive enzymes. PM me if you want to know what it is. I'll need to look it up.