Symptoms: Sometimes the symptoms are vomiting, abdominal pain, poor appetite, or even alternating constipation and diarrhea, or fecal incontinence, bloody stools. Constipation: Strictly speaking, it is about the hardness of the stools, and has nothing to do with the frequency of defecation, and the causes are divided into functional (90%) and organic. Functional triggers 1. Habitually holding back the urge to defecate, resulting in the receptors near the anus being slowed down, which reduces the defecation reflex 2. Low intake of vegetables and fruits, and high-fat, high-protein foods inhibit peristalsis 3. Medications, nasal allergy medications, and lead-containing acidulators 4. Irregular daily routine 5. Poor parent-child interactions or frustration with the defecation training process, which can make the child fearful of defecation 4. Common: anal fissure Neurological/muscular disorders: megacolon, myelopathy, autoimmune diseases Endocrine: hypothyroidism, hyperthyroidism Electrolytes: hypokalemia, intestinal obstruction, chronic lead poisoning.