If a 4-year-old baby is angry, he can adjust his diet first. You can drink more chrysanthemum tea or mung bean water, eat more fruits with laxative effect such as bananas, pitaya, apples and pears, and do proper exercise every day to effectively promote gastrointestinal peristalsis. If diet can't relieve symptoms, you can give your child probiotics, regulate gastrointestinal flora, increase gastric motility and relieve your child's symptoms.