Rumination disorder: Effoless and painless regurgitation of paially digested food into the mouth soon after a meal, which iseither swallowed or spit out According to DSM-5, the disordermust be present for at least 1 month after a period of normal functioning, and not better accounted for by gastrointestinal illness, or psychiatric or medical conditions. Can be observed in normal infants It's a functional gastrointestinal disorder Occurs between 3 months and 12 months of age.