Oooh, you may want to switch from WOW chips to baked chips. Fake fat is no friend to the IBS colon!
Have you looked at all the recipes on the recipe board? Could you find some of the quick bread recipes you could make on your own or with your parents? Also, have you tried the amazake rice drinks? www.amazake.net 400 calories per bottle and pretty yummy!
Oooh, as for pasta sauces, I just get organic ones with low fat. Or my husband just throws in a bunch of yummy things like Italian tuna and capers with a tiny bit of olive oil with the pasta....