Hi Rcharette,With IBS, it's difficult to suggest foods to gain weight, as you haven't identified which foods increase your IBS.But, in general, fats are the highest calories, so even an extra tablespoon a day, (1 tsp. per meal/snack 3 times a day) would boost your total calories significantly. But it has to be one you tolerate well, and fats are often a problem with IBS. Flaxseed oil is generally not very reactive, you may try adding it, and rotating it with some other oils, like almond or canola. (Don't eat the same things every day, or you risk increased food sensitivities down the road.)Do you tolerate nut butters? Peanut, cashew or almond butter? Spread on white toast with a bit of jelly?Do you tolerate juices of any kind? They are a great way to increase calories easily. (Too much juice is a major culprit in obesity for many people.) Again, fructose or a particular fruit may make things worse. . . or not. Just sip throughout the day.Have you ever tried a gluten free diet? SOMETIMES, people find they get better in as little as 4 days on a gluten free diet. So, if you do gluten free, and get a LOT better in 3-4 days, GREAT! However, IF you don't get any better, it doesn't prove ANYTHING. (Some people who are gluten sensitive have to elimnate it for 6 months before they see results.
)Finally, don't just eat 3 meals a day, but have snack foods on hand, in your car, at work. . . etc. and be sure to eat 5-6 times a day.Anyway, just a few tips.