The following is based on the NICE guidelines
Gastro-oesophageal reflux (GOR) is the passage of stomach contents into the oesophagus and a normal physiological process in infants. It is common in young infants who have a liquid diet, spend much of their time lying down, and do not have a fully developed oesophageal sphincter. It usually begins before 8 weeks of age, and 5% of infants will have 6 or more episodes per day. GOR does not need investigation or treatment, and is managed by advising and reassuring parents.
Gastro-oesophageal reflux disease (GORD) occurs in a small proportion of infants and is when GOR is associated with distress or complications. There is no reliable test to distinguish between GOR and GORD. GORD may be present if an infant has obvious distress during and after feeds, starts to refuse feeds (food aversion), coughs or chokes with feeds, develops a hoarse voice, or adopts unusual positions whilst feeding. Most infants with GORD can be managed in primary care.