If you know your tummy troubles stem from constipation, London also recommends drinking a cup of joe first thing in the morning. Research has shown that caffeine plus coffee’s plant-based antioxidants can help you stay regular. Avoid caffeinated beverages if you’re sensitive, or feeling nausea or reflux unrelated to constipation. (Coffee, however, is not a good idea for people for whom acid upsets their stomach, says Freuman.)