I know some of you have dealt with this before, so I am seeking the wisdom of the board. Up until yesterday both of my 10 week old boys have been doing just fine with solid stools. Jack started having diarrhea yesterday, and now both he and Clark have loose stools. Jack even had a little bloody tinge just barely on his last one. What could cause both to get diarrhea suddenly with no change in diet? They are both just as active and playing. Any advice is appreciated.