I can understand your concern.
Certain deficiencies like iron, folic acid, protein deficiency etc can be the cause of this issues and they need to be taken care of with a proper diet.
Give him a high fiber food along with fruits and vegetables.
Give him syrup. Bevon 5ml once a day after food and syp. Glutanase 5 ml once a day after food.
Consult a pediatrician for further evaluation and management.
Dr. Anil kumar jain.