An upset stomach is when our tummy is rumbling and/or when we are experiencing cramps or gas. Indeed, too much gas is a frequent cause of upset stomach. The associated pain is caused by bloating and excessive tension of the digestive muscles. These symptoms are harmless but very troublesome over time. Gas in the gastro-intestinal tract is perfectly natural. In fact, carbon dioxide gas is formed in the stomach, and bacteria in the bowel during digestion produce gases such as methane, hydrogen and nitrogen. Also, we swallow air while eating, drinking or even speaking. Stress, lack of exercise or eating certain foods may lead to excessive accumulation of gas in the gastro-intestinal tract. Too much gas in the stomach may result in heartburn, burping and fullness. Gas accumulating in the lower section of the gut may cause bloating and intestinal cramping. Many plants can help relieve digestive symptoms.