Onion contains sulfide, etc., there is a certain degree of irritation, eating onions will fart, may be eating too much, may also be caused by intestinal flora imbalance. 1. Eating too much: onions contain sulfide, carbon dioxide and other substances, eating will produce sulfur dioxide and other gases, eat more of these gases can not be fully absorbed, discharged from the body, farting. This is a normal physiological phenomenon, stop eating can be relieved, usually can eat fried onions, pay attention to the amount of onions, avoid eating too much. 2. Intestinal flora imbalance: onions have a certain degree of irritation, if the gastrointestinal flora imbalance, eating onions will stimulate the gastrointestinal tract, affecting the normal digestive function, the harmful bacteria decomposition of food produces gas, there will be farting, and there may be abdominal bloating, loss of appetite and other symptoms. You can use Lactobacillus and Bifidobacterium to promote the growth of beneficial bacteria and improve intestinal flora. Eating onions and farting excludes physiological reasons such as eating too much, you should consult a doctor in time to find out the cause under the guidance of the doctor and carry out reasonable treatment.