Air swallowing as a cause of gaseous abdominal distention in an infant care

Yu-ming Fu 符儒明, Michael K L Wong 黃加霖, Michael W F Lau 劉永輝

HK Pract 2007;29:63-65

Summary

Air swallowing or aerophagia is a functional gastrointestinal tract disorder, occurring both in adult and paediatric population. It usually presents as abdominal pain or distension. After exclusion of organic gastrointestinal disease, recognition of its occurrence and generally good prognosis can reduce unnecessary parental anxiety and investigations. We present here a 5 week old infant with clinical features of air swallowing and a review of the condition.

摘要

空氣吞嚥是一種功能性腸胃疾病，可見於成年或兒童，多表現為肚痛或肚脹。確認病因和解釋此病預後良好。 可以減少家長不必要的焦慮和不必要的檢查。本文敘述了一位患本病的五個星期大嬰兒的臨床表現並就本病進行回顧。

Introduction

Air swallowing (or if chronic, aerophagia) is a functional gastro-intestinal disorder in which patient usually presented with abdominal distension or abdominal pain.¹ It is a common disorder in adult population which also occurs in paediatric population.^1-8 However aerophagia in paediatric population was seldom discussed in literature especially its occurrence in neonates and infants. We present here a 35-days old previously healthy infant with clinical features of aerophagia together with a review of this condition and its differential diagnoses.

Case report

A 35-day-old boy, who had been healthy since birth, was admitted through Accident and Emergency department as he was noticed by the mother to have abdominal distension and increase crying for 2 days. He had no vomiting or constipation. There was no complication in his perinatal period including delay in passing meconium. He was on breast-feeding with supplementary artificial formula at night. There was no recent change in bowel habit with bowel opening 3 to 4 times per day and normal non-blood stained stool. He was not on any medication. Further history revealed that the patient had prolonged crying before feeding. No excessive flatus was noticed by his mother.

Physical examination showed an active baby with good hydration status and satisfactory growth parameters. Abdomen was distended but soft and non-tender with no mass or hernia. Anal tone was normal with no gush of stool after digital rectal examination. Bowel sound was normal. Other systems were unremarkable. Initial abdominal X-ray showed distended bowel without fluid level (Figures 1).

Patient was kept nil by mouth with maintenance intravenous fluid. Abdominal distension gradually subsided with repeated serial abdominal X-ray showed decreasing distension of bowel. General condition of the patient remained well since admission and blood tests including amylase, liver function test, renal function test. calcium level and white cell count were normal. Feeding was thus resumed and the baby was observed by experienced nursing staff to have excessive air swallowing. Feeding was otherwise good with normal bowel opening. Diagnosis of air swallowing was made and preventive measures to avoid air swallowing and excessive crying were advised to parents. Patient was stable and discharged on day 3 of hospitalization. Follow-up assessment showed no recurrence of abdominal distension, with satisfactory weight gain.

Discussion

Aerophagia means excessive air swallowing, which may cause excessive gas in intestine (aeroenteria) and thus gaseous abdominal distension. It is a poorly characterized gastrointestinal disorder probably functional in origin.¹ It is a common disorder seen by adult gastroenterologists^3-8 but aerophagia in paediatric population was seldom discussed in the literature.³ The most common presenting symptoms in paediatric patients were abdominal pain and abdominal distension.^1-2 Other symptoms include belching, excess flatus, fullness or bloating after eating and air swallowing.¹

Rome II committee, an international committee which review the literature and provide consensus symptom-based criteria for diagnosing functional gastrointestinal disorders including aerophagia, defined diagnostic criteria for aerophagia as at least 12 weeks of symptoms, that need not be consecutive, in the preceding 12 months with two or more of the following symptoms: (i) air swallowing, (ii) abdominal distension due to intraluminal air; and (iii) repetitive belching and/or increased flatus.⁹ Recently, there was an update of Rome II to Rome III criteria with required duration from 12 weeks to 8 weeks.¹⁰

However a recent retrospective study on paediatric patient diagnosed to have aerophagia in the past 28 years found that more than half of patients did not fulfill the Rome II committee criteria. Most of those patients failed to fulfill the criteria of having 12 weeks symptoms but they had no significant difference in terms of outcome from those who fulfilled Rome II committee criteria.¹ This suggests that duration of symptom may not be crucial in diagnosing aerophagia in children.

In this case report, a 35-day-old boy had symptoms typical of aerophagia with gaseous abdominal distension with documented excessive air swallowing during feeding with duration of only 2 days. He probably has air swallowing all along because of inadequate maternal feeding skill causing abdominal distension, abdominal pain and crying. This led to a viscous cycle of further air swallowing and distension. Differential diagnoses including surgical emergencies like intestinal obstruction, malabsorption like lactase deficiency, Hirschsprung's disease and other GI organic diseases should be considered.

Essentially normal physical findings and non-distended bowel on serial abdominal X-ray make surgical emergencies less likely. Malabsorption like lactase deficiency may cause excessive gas production inside intestine but it will also cause diarrhoea that was absent in our patient. A satisfactory growth history and normal physical examination favoured functional GI disorder and make malabsorption as well as other GI organic diseases less likely.⁹ Our patient had no delay in passing meconium, normal anal tone and normal bowel opening as observed in hospital, which made Hirschsprung's disease less likely. Therefore although this case failed to fulfill the Rome II committee criteria, the clinical picture was still compatible with the diagnosis of aerophagia. Recognizing the occurrence of air swallowing or aerophagia in neonatal and infantile period is important. Explanation to parent that it is probably functional rather than organic in origin,¹ that sometimes it may persist for up to more than 2 years¹ and it's prognosis is generally good,¹ all help in relieving parental anxiety. Management consists of reassurance and explanation of the symptoms for the parents and child. For older children, excessive use of chewing gum or carbonated beverages should be discouraged. Problems causing stress and anxiety should be promptly addressed. Behavioural therapy and drug therapy (e.g. aluminium hydroxide, simethicone, chlordiazepoxide) have been tried but their efficacy have not been properly tested.¹

Conclusion

Air swallowing or aerophagia is common in adult population and is rarely discussed in neonatal and infantile period in the literature. Recognizing it's occurrence in neonatal and infantile period is important as explanation on its benign nature, sometimes prolonged disease course and general good prognosis helps in relieving parental anxiety.

Key messages

1. Air swallowing or aerophagia is a functional gastrointestinal disorder of generally good prognosis.
2. Rome III committee criteria of aerophagia require 8 week of symptoms of air swallowing, abdominal distension and repetitive belching/increased flatus.
3. In young infant, exclude organic gastrointestinal disorders e.g. intestinal obstruction and lactase deficiency is needed.
4. Recognition of its occurrence can reduce parental anxiety and unnecessary investigations.