Our son has a definite allergic reaction to sweet potatoes! As a baby he was violently sick from sweet potatoes three times on three separate occasions-months apart (we thought it was the flu - but then I just stopped buying baby food sweet potatoes.) Now as a five year old, he has eaten sweet potatoes twice in the last two months and both times has become violently ill with a terrible amount and force of vomitting. Within about 4 hours he has bounced back - so we...