My 4months old son suddenly stopped drinking formula milk . I have been giving him NanPro stage1 since he was one month old as my milk was not sufficient to him. But suddenly he has stopped taking formula feed. He cries so much when I feed him using pallada(katori spoon) . Even with bottle also , he cries so loudly and hold his breath. What could be the issue? Again please don’t advise me to give only breastfeed as I have already told you that it’s not sufficient for the baby even with cluster feeding.