Iím not really sure of the USDA zone for Salvia hispanica. Iíd say zone 9 based on this info showing Texas and Florida: http://plants.usda.gov/java/profile?symbol=SAHI6 For the most part, as mentioned in the article, from what I can gather, S.hispanica does best outside the USDA zones (in Guatemala, Mexico, Argentina, Australia etc), which is why commercial growers donít grow it here. I bet you could grow it in KS though. It just wouldn't bloom until the end of the season and may not set seed before a killing frost. Our Tarahumara Chia (S.tiliifolia) just started blooming yesterday!
As for causing stomach and bowel problems
Chia is a seed containing fats and dietary fiber. There are medical conditions that cause some people sensitivities. For healthy individuals, one tablespoon, or less, per day of chia in foods should not be a problem. I always recommend seeing a doctor or healthcare professional for stomach and bowel (or any health) concerns.