Hello, I have gone through your query and understand your concern. There are plenty of causes for constipation in children. Some common causes are diets low in fiber, medications like narcotics or antacids, ignoring the urge to have a bowel movement, specific diseases and conditions, functional GI disorders like toilet training, weaning from breast milk and introduction of solid food etc. Otherwise nothing to be concerned. He need the multifactorial approach. 1. Diet changes Increase his liquid intake. Add plenty of fiber containing fruits and vegetables. Do not encourage snacks, meat and other processed foods. 2. You should be encourage to use the toilet shortly after meals to promote regular stool passage 3. Final option are laxatives and enema if both of the above not works. 4. Withdraw the medications causing constipation. Thus treat him wisely. As your doctor said, it is mostly due to diet. But not only limited to diet and other factors like Toilet training, ignoring the urge to have a bowel movement, Introduction of new foods like solid foods, Avoid using bathroom. All may cause the constipation in child. As he usually passes stool in 3 to 4 days, nothing to be concerned. You should be concerned about this, if he have fever, any vomiting, blood in the stool, a swollen abdomen, weight loss. Then he need the further examination and investigation to find the cause and further treatment. Hope this helps. Please write back for further queries. Wishing you good health.