Hi there... I dont have too extensive of a cookbook collection, but did look online and found a couple of sites for veggie won ton soup...
At this site, they recommend a veggie won ton soup with noodles (the gal actually adapted a meat recipe by replacing with tofu...but everything here seems pretty IBS safe, and they use cornstarch and water for the "glue" to hold the won tons together) http://regency.estarcion.com/~mt/gastronome/archives/000777.html
Also, at this site, they have another variation of veggie won ton soup...just click on the "won ton soup" link...it will direct you to refer to the "crispy won tons" link for the won ton manufacturing It seems pretty IBS safe, except you might want to leave the bok choy/ cabbage out since it only boils for 2-3 minutes (or else cook it for a really long time to make it more soluble) http://www.geocities.com/NapaValley/6927/chin.html
And last but not least, this one sounds really good, except for the use of egg in sealing the won tons (I would use the cornstarch and water as recommended in the site above). http://vegetarian.about.com/library/soups/blwontonsoup.htm
And for those of us who would rather not assemble 25 little intricate works of art, (from what I've read on this board, this would be right up Lana Marie's alley - you can just use a can of veggie broth and throw in some low fat veggie pot stickers from Trader Joe's (if they happen to be in your area) and some cut up scallions....This sounds to me just as delish and more suited to my lifestyle...plus I love Trader Joes!!