Wanted to know which formula milk is easily digestible, enfamil , similac or dexolac?

This varies with each baby. Breast milk is the preferred feed as it is designed specifically for the baby you have. Any or all alternative commercial formulas may be well tolerated by some babies while others spit more/are constipated or have other minor symptoms. You can try several, at least a week at a time, to see which baby thrives with. When you find one they tolerate well, stick with it.