Bloated stomach causes sickness when GAS builds up in your digestive system.. This can cause DISCOMFORT, pain and nausea.. Bloating can be caused by EXCESS air intake, eating too MUCH or certain medical conditions.. To reduce bloating, avoid carbonated drinks, chewing gum and certain FOODS.. Eating slowly and staying hydrated can also help.. If bloating persists or is accompanied by other SYMPTOMS, seek medical advice..