I haven't read much of the posts but I too suffer from IBS and found this on the net. Hope it helps
BAD food - FAT is the worst thing
Whole wheat flour, whole wheat bread, whole wheat cereal
Wheat bran
Whole grains, whole grain breads, whole grain cereals
Granola
Meusli
Seeds
Nuts
Popcorn
Beans and lentils (mashed or pureed they're much safer)
Berries (blueberries, strawberries, blackberries, cranberries, etc.)
Grapes and raisins
Cherries
Pineapple
Peaches, nectarines, apricots, and pears with skins (peeled they're much safer)
Apples (peeled they're safe)
Rhubarb
Melons
Oranges, grapefruits, lemons, limes
Dates and prunes
Greens (spinach, lettuce, kale, mesclun, collards, arugala, watercress, etc.)
Whole peas, snow peas, snap peas, pea pods
Green beans
Kernel corn
Bell peppers (roasted and peeled they're safer)
Eggplant (peeled and seeded it's much safer)
Celery
Onions, shallots, leeks, scallions, garlic
Cabbage, bok choy, Brussels sprouts
Broccoli
Cauliflower
Tomatoes (peeled and seeded, especially raw, they're much safer)
Cucumbers (again, peel and seed them and they're much safer)
Sprouts (alfalfa, sunflower, radish, etc.)
Fresh herbs
FAT
Good Food rough in order of goodness
Rice
Pasta and noodles
Oatmeal
Barley
Fresh white breads such as French or sourdough (NOT whole wheat or whole grain)*
Rice cereals
Flour tortillas
Soy
Quinoa
Corn meal
Potatoes
Carrots
Yams
Sweet potatoes
Turnips
Rutabagas
Parsnips
Beets
Squash and pumpkins
Mushrooms
Chestnuts
Avocados (though they do have some fat)
Bananas
Applesauce
Mangoes
Papayas (also digestive aids that relieve gas and indigestion)