What Can A Child Suffering From Gas And Loose Motions Be Given?

My son is 2 month old. He had loose motions he ws taking Farex. He doent take breastfeed. Then we switc to isomilk. Now he dont have loose motions. But he has gas problem. He has motions which is semi solid. His weight is also less I.e 3.7 kg. Plz advise can we give him himalaya bonnisan to help him frm gas n to gain weight. We r already giving him colicad when he cries a lot.