Help me out. Feed him bottle or spoon?

I lost my 2.5 old month son on 18 april. He was suffering from major health issues ,he was completely normal 3 kg baby on mixed feed similac and mother feed. On 24 day he got diarrhoeal issue which led to dehydration. he got rehydrated but diarrhoea was persistent.we traveled to Hyderabad for better option. All relevant major test were carried on from every blood test and biopsy of stomach tissue even genetist test . Nothing came out. Thrombocytopenia and stomach distension reason remained unknown till date. I am in great pain with many doubts for life time. Can you just help me with one doubt? Doctors from you I just wanna know can a baby achieve all milestone of growth on formula feed? Then how to feed him bottle or spoon? In case mother's milk is not available just answer this question without any further questions