No real consensus exists as to what colic is. Some definitions are unstoppable crying for more than 4 hours, usually in the evening starting at about 3 weeks and ending by 16 weeks. Others state that 6 hours or more define colic. A cycle of gas and crying ensue. X rays have shown that crying introduces air into the digestive track, so burping the baby while crying may be a good idea.
Products containing simethicone reduce trapped gas and are very safe for baby, as it remains inert.
One theory about colic is that undigested milk proteins ferment and create gas, again the anti gas drops can be helpful here. 2 Peppermint drops in 4 oz. There are some homeopathic solutions, my preference is Hylands Colic or Teething tablets. They are made to melt on baby's tongue so are easy to use. They remain helpful for teething bouts sure to come later.