My Son Is Three Months Old He Has Gas Trouble

My son is three months old
He has gas trouble ......he pulls his legs up while sleeping n struggles to sleep during day time and in morning after five .....
Once he wakes up from sleep he stretches his legs n tightens his stomach ....
My Dr said after three months he ll be fine
Only mother feeding
Bowel movements are regular
Will it affect him In future
Havent given him colic aid and carmopeptine drops
My mother is not interested in giving him drops
She says he is better now
I'm confused is it fine without drops
Please help me doctor