Gripe water is available otc, but babies sometimes (rarely, but does happen) have an allergic reaction to one or more of the ingredients in it.
There are also anti-gas drops available, but my understainding is that you should discuss use and dosage with a pediatrician first. If reflux is causing the colic (a doctor should diagnose), there are medications for that, but they should be prescribed by your baby's doctor and not picked up from a chemist without a prescription and doctor visit (overdose or use of the wrong drug is very dangerous with babies under 6 months but pharmacies here seem to sell anything to anyone...)
Has your pediatrician recommended anything? If your baby is on formula, there are special formulas that are easier to digest, lactose free, etc. for specific conditions that may be causing the colic symptioms.