Hi there,
Not sure if it's bland because I've never tasted it, but I feed Sammy Dr. Harvey's Organic Canine Health. You can check out this thread where someone else who feeds Dr. Harvey's to their Yorkie mentioned that it helped with their furbaby's IBS:
http://www.yorkietalk.com/forums/showthread.php?t=72865
The great thing about it is that you add your own protein and oils so I suppose you can make it pretty bland by not adding either. Here is a link to their site:
http://www.drharveys.com/dogs/caninehealth.asp
And this is where I order from:
http://www.naturespet.com/
Hope this helps!