My 18 month son has problem of constipation. He finds it very tough to pass the stood because it gets so hard and he avoids to do it. He is mostly taking cow milk and little food. When we give him methi powder and liquid paraffin then he feel relaxed and passes the stool normally but we are giving from last 6/7 months. Now we want to stop it. Pls advise how can we get in the situation to pass the stool normally without medicines.