Gastro-oesophageal Reflux in Infants: Investigating this Common Condition (Part 1)

Infantile reflux is a physiological process of regurgitation. This is where some of the baby’s feed effortlessly returns into their mouth from their stomach. ‘Physiological’ denotes the normal, healthy operation of the body. According to the National Institute for Health and Care Excellence (NICE) physiological reflux usually begins before the infant is 8 weeks old and is highly prevalent with 50% of babies experiencing it once or more a day during their first 3 months.

Physiological reflux changes to Gastro-oesophageal reflux disease (GORD) when the reflux of gastric contents causes troublesome symptoms or complications. A prospective study set in general practice found that the physiological symptoms of reflux usually stop when the baby reaches 12-14 months of age, with a peak incidence occurring at 4 months of age.

Infants communicate their needs and distress via crying. Determining whether crying is caused by a troublesome symptom of GORD can be challenging and may result in infants with harmless symptoms of reflux being incorrectly diagnosed. This outcome could result from episodes of physiological reflux occurring at the same time, by chance, as a period of crying and subsequently a causal relationship could be misinterpreted. This is compounded by the high prevalence of physiological reflux in this age group.

The result is a blurring of the boundaries between the definition of physiological reflux and GORD and controversy regarding diagnosis, leading to the potentially inappropriate use of drug therapy in healthy infants. This concern is important because physiological reflux is a self limiting, temporary condition that improves with growth, and in addition, data suggest that few of the drugs used to treat infants with GORD are licenced for this use.

Temporary condition that improves with growth

Infantile reflux is caused by transient relaxation of the circular band of muscle (sphincter) at the junction between the oesophagus and the stomach. As a baby grows, this sphincter fully develops and is able to close. This allows the sphincter to act like a valve: relaxing to allow food and fluid to go down and tightening to prevent fluid, food and acid leaking up (refluxing). As a result both physiological reflux and GORD are conditions that infants will grow out of. According to evidence only 5% of infants experience reflux at 10-12 months, compared to 50% at 0-3 months.

This improvement observed with increasing age is also due to:

- Growth in the length of the oesophagus

- More upright posture

- Increased stomach capacity

- More solid diet

Physiological reflux and GORD are more common in babies who:

- Were born prematurely

- Had a very low birth weight

- Have severe neurological impairment

Research shows the prevalence of physiological reflux to be similar in breastfed and formula fed infants.

close-up portrait of a beautiful sleeping baby on white

Other potential causes

Slow digestion associated with delayed gastric emptying and cow’s milk protein allergy/intolerance (CMPA) have also been identified as potential causes. It is significant that research has identified that up to 40% of infants with physiological reflux have CMPA. This is due to CMPA causing similar symptoms to physiological reflux and because CMPA is itself a cause of reflux.

A rare cause of reflux may be a blockage or narrowing within the baby’s gastrointestinal system. Within the oesophagus this is known as an “oesophageal stricture”. Between the stomach and the small intestine this is known as a “pyloric stenosis”.

Diagnosis

Diagnosis of physiological reflux and GORD is usually made clinically: on the basis of signs and symptoms alone. However, no symptom or group of symptoms reliably identifies infants that are likely to respond to treatment.

NICE guidelines advise to suspect GORD in infants with either (but usually both) of the following:

- Frequent and troublesome regurgitation or vomiting (which may occur up to 2 hours after feeding).

- Frequent and troublesome crying, irritability or back-arching during or after feeding, or feeding refusal (despite being willing to suck on a dummy, if used).

Poor weight gain is also identified within the literature as a troublesome symptom that can be associated with GORD. In some cases referral for further investigation is required.