Most babies, by one year of age, outgrow most of their gastroesophageal reflux symptoms. She cries a lot and nothing seems to comfort her. In the first three to four months, colic is a common cause of a bellyache. We don't really know what really causes the colic. It is typically seen in normal babies that cry a lot.
Nobody knows why.
There are medications for bellyache colic. Some work, some don't. These interventions include antispasmodics, changing formula from milk to soy, carrying baby around, rubbing baby's back and patience. They are typically big healthy babies and often boys. They can last one to two weeks.