You had a baby, and now you are hearing the word reflux often. What the heck is reflux and what does it mean? In its simplest form, reflux (AKA GERD) is the involuntary regurgitation of stomach contents (sometimes including stomach acid) into the esophagus. The ability of the human body to move stomach contents into the esophagus is completely normal AS A PROTECTION mechanism. However, ongoing, and repeated regurgitation is far from normal. Regurgitation always happens for