The act of swallowing air is widespread and usually unconscious to people. It often occurs when people eat, drink, and swallow saliva. In infants and toddlers, air swallowing is common when children cry, suck on a pacifier, or feed themselves improperly, while in older children, air swallowing is common when drinking liquids through a straw or chewing gum. Screening for air swallowing can be based on the following symptoms 1. Abdominal distention Children with gas swallowing disorder have recurrent abdominal distention due to swallowing large amounts of gas. The child’s abdominal distension has the following characteristics: the abdominal circumference is the smallest when waking up in the morning, and the distension is the lightest; during the day, the abdominal circumference gradually increases, and the distension gradually worsens; at night, it is the most serious when falling asleep; at night, the distension gradually decreases, showing the characteristics of “light in the morning and heavy at night”. 2. Repeated belching Due to excessive swallowing behavior, the stomach of children with gagging syndrome is always dilated, causing repeated belching. In normal cases, people experience brief gastric distention about 20 times a day, and the amount of gas per hour usually does not exceed 100 ml. In children with gagging disorder, anal gas is more frequent than in normal children because of excessive gas swallowing. Due to the increased exhaustion during sleep and the absorption of some of the gas by the gastrointestinal tract, the abdominal distention of the child gradually decreases at night and is at its lightest or even disappears when he or she wakes up in the morning.