I don't have IBS, but I am severely gluten-intolerant; it crept up on me when I hit 30. It was a gradual thing that got to be horrible after about a year. I don't just have bloating etc., I throw up and am in agony for up to 6 hours if gluten gets inside of me. Thankfully, due to being very careful, I haven't been sick in a few years.
I actually consider the fact that I got this as a blessing in a way. Many people, after 30, put on weight and get unhealthy if they continue to eat the way they did in their teens and don't exercise. I always ate fairly well, but after getting this I eat super healthy now; no cakes, pies, cookies etc. I will sometimes indulge in the odd GF cookie etc., but not often.
So some of the foods I eat are:
Lots of vegetables (broccoli, peas, cauliflower etc.)/squashes/salads
Chick peas (I make lots of hummus), lentils, and other beans (I make an awesome black bean soup with chicken and brown rice)
Brown rice (and other rices), brown rice pasta (when I have pasta)/brown rice bread (I buy El Peto mix for my bread maker)
Very little red meat. Lots of chicken, fish, eggs, and tofu.
Lots of water. Very very little pop (may have 1 diet coke per week)
So a typical day may look like this:
Breakfast
Fruit smoothie made with lots of fresh and frozen fruit/yogurt/honey/tofu or a slice of brown rice toast with soy butter or peanut butter
Lunch
A soup I've made (maybe butternut squash or black bean etc.)
Maybe some tuna salad wrapped in lettuce
Dried fruit for dessert (sometimes I will have chocolate...)
Dinner
Chicken, roasted potatoes, salad
Nighttime
May make some air popped popcorn while watching something
I eat very little processed food; most of the food we eat at home is prepared by myself. It becomes second nature very quickly. I pass by McDonalds and really wonder how I could have ever eaten there.