The effect of food withdrawal in children with rapid-transit constipation

Cows' Milk Allergy-Associated Constipation: When to Look for It? A Narrative Review

Constipation is a very common disorder, mostly functional in nature, that may persist for years in up to 35-52% of children. Food allergy prevalence, severity and persistence are increasing over time, and cows' milk protein is the commonest food allergen recognised to affect gastrointestinal motility in children. There is mounting evidence of the role of cows' milk (CM) allergy (CMA) in children with constipation. With this narrative review, we aim to provide clinicians with an updated and critical overview of food allergy-associated constipation. We searched Embase, Medline and the Cochrane Library, using keywords related to the topic. Only reviews and studies including children aged 0-17 years that were published in English were considered. Constipation has been reported in 4.6% of infants with CMA; the prevalence of food allergy underlying chronic constipation in children resistant to conventional treatment and presenting to tertiary clinics ranges between 28% and 78%. The identification of predisposing risk factors and of a specific phenotype of food allergy-induced constipation remains elusive. No allergic tests, radiological or motility investigations achieve sufficient sensitivity and specificity to screen children for CMA-related constipation. A 4-week cows' milk protein (CMP) elimination diet may be considered for children with chronic constipation resistant to conventional treatment and who lack alarm sign/symptoms of organic diseases. In subjects with ameliorated symptoms on CMP elimination, the diagnosis of CMA should be confirmed by a food challenge to avoid an unnecessary protracted diet.

'Rapid transit' constipation in children: a possible genesis for irritable bowel syndrome

Children with chronic idiopathic constipation (CIC) often end up at the surgeon when medical treatments have failed. This opinion piece discusses a recently described pattern of CIC called 'Rapid transit constipation (RTC)' first identified in 2011 as part of surgical workup. RTC was identified using a nuclear medicine gastrointestinal transit study (NMGIT or nuclear transit study) to determine the site of slowing within the bowel and to inform surgical treatment. Unexpectedly, we found that RTC occured in 29% of 1000 transit studies in a retrospective audit. Irritable bowel syndrome (IBS) occurs in 7-21% of the population, with a higher prevalence in young children and with constipation type dominating in the young. While 60% improve with time, 40% continue with symptoms. First-line therapy for IBS in adults is a diet low in fermentable oligosaccharides, disaccharides, monosaccharides and polyols which reduces symptoms in > 70% of patients. In children with functional gastrointestinal disorders, fructose intolerance occurs in 35-55%. Reducing fructose produced significant improvement in 77-82% of intolerant patients. In children with RTC and a positive breath test upon fructose challenge, we found that exclusion of fructose significantly improved constipation, abdominal pain, stool consistency and decreased laxative use. We hypothesise that positive breath tests and improvement of pain and bowel frequency with sugar exclusion diets in RTC suggest these children have IBS-C. These observations raise the possibility that many children with CIC could be treated by reducing fructose early in their diet and this might prevent the development of IBS in later life.

Dietary exclusion of fructose and lactose after positive breath tests improved rapid-transit constipation in children

Aims

Exclusion of fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) from the diet is effective in alleviating symptoms of irritable bowel syndrome (IBS) in adults. Rapid‐transit constipation (RTC) is a recently discovered subset of chronic constipation and has been linked to food intolerance. The aim of this study was to audit the effect of specific FODMAP elimination diets in children with RTC.

Methods

This was an audit of children presenting to a tertiary children's hospital surgeon with refractory chronic constipation who had rapid transit in the proximal colon on nuclear imaging; had hydrogen/methane breath tests for fructose, lactose, and/or sorbitol intolerance; and were advised to exclude positive sugar under clinical supervision. Patients filled in a questionnaire rating severity of constipation, abdominal pain, and pain on defecation with a visual analogue scale (VAS, 0 = none, 10 = high) and stool consistency for 6 months before and after dietary exclusion.

Results

In responses from 29 children (5–15 years, 21 males), 70% eliminated fructose, and 40% eliminated lactose. There was a significant reduction in the severity of constipation (VAS mean ± SEM, pre 5.8 ± 0.5 vs post 3.3 ± 0.6, P < 0.0001), abdominal pain (5.1 ± 0.6 vs 2.8 ± 0.5, P = 0.0004), pain on defecation (5.8 ± 0.6 vs 2.6 ± 0.5, P < 0.0001), and increase in stool wetness (Bristol Stool Scale pre 3.3 ± 0.3 vs post 3.9 ± 0.2, P = 0.004).

Conclusion

Children with RTC showed significant improvements in constipation and pain after excluding the sugar indicated by positive breath tests, suggesting that specific sugar‐exclusion diets may have a role in the management of RTC in children.