Farts are intestinal gases discharged from the body after metabolism, mainly unintentionally swallowing too much air gas, and intestinal flora metabolize food, which undigested nutrients produced by the gas. So in the consumption of purple potatoes after the emergence of the exhaust is not actually in the detoxification, purple potatoes contain oxidizing enzymes, eat too much purple potatoes will lead to the patient to appear bloating, the emergence of the exhaust. And sweet potatoes are rich in starch, starch into the intestinal tract will easily be decomposed into a large amount of gas, the emergence of exhaust. Therefore, after eating sweet potatoes, the situation of exhaust is not caused by excessive toxins in the body, but because of the phenomenon of intestinal peristalsis to digest sweet potatoes. For patients with gastrointestinal problems need to minimize the consumption of sweet potatoes, to avoid sweet potatoes on the intestinal tract to stimulate lead to excessive gastric acid.