Appendix 14 – Constipation, Coeliac screening (including HLA typing) and gastroenterological complications

Background –

There are a number of conditions that are more common in Down Syndrome.  These include gastro-oesophageal reflux disease (GORD), Hirschsprung’s disease, pyloric stenosis, duodenal atresia, aspiration, coeliac disease, constipation and food allergies.  This presentation gives an excellent overview and covers everyone is considerable detail.  https://www.dsmig.org.uk/wp-content/uploads/2017/12/RCPCH-SIG-Gastrointestinal-manifestations-of-Down-syndrome.pdf

In particular, these 3 conditions need to be highlighted as the most common and also ones that need to be assessed and managed at every patient review by clinicians:

GORD – signs, symptoms, red flags, investigations, management, when to refer.

Coeliac disease – symptoms, signs, investigations and management, when to refer.

Constipation – recognition, management and behavioural interventions.  As this is often a major issue for many, the slides have been copied out below: 

Constipation:

Stooling issues and DS 

  • Constipation Prevalence 20-36% – Increased with hypotonia, communication and behaviour issues, supplementary feeds.  Constipation can happen early on due to low muscle tone, poor mobility, diet and inadequate fluid intake etc or even short segment Hirschprungs.  Need to exclude organic disease.  Need to check for and manage possible overflow +/- stool withholding which are common issues.  

  • Diarrhoea: often due to overflow.  But could be due to stimulant laxatives. If infective is associated with initial pyrexia.  Consider gut dysbiosis associated with lactose intolerance/malabsorption. 

Triggers for constipation: 

  • Varies between children

    • Elucidate in the history: age of onset. 

    • Parental expectations: address them in the treatment strategy. 

  • Also consider: pain (e.g. a fissure) • Fever/dehydration • Dietary intake (in terms of fibre content) • Psychological issues and expression of distress • Toilet training/aversion • Other medicines, other conditions • Family history of constipation.  

NICE recommended treatment 

  • Investigate children with red flags 

  • For faecal impaction – NICE: Polyethylene glycol 3350 + electrolytes (e.g. Movicol Paediatric Plain) • Escalating dose regimen (= first-line treatment). • Adjust the dose of Movicol according to response. • Risk of increased overflow (consider impact on school). • Review soon • Reduce the dose of Movicol when disimpaction is achieved – Maintenance dose might be half disimpaction dose. • BUT.... 

  • Add stimulant (senna/picosulphate) if Movicol alone does not work (but can cause overflow++).  

  • Substitute a stimulant laxative if Movicol is not tolerated.  • Add another laxative such as lactulose (toddlers) or bisacodyl (older children) if stools are hard.  

  • Medication may be needed for weeks/months.  • Children who are toilet training should remain on laxatives until toilet training is well established.  • Gradually reduce the dose over a period of months in response to stool consistency and frequency; and increase if symptoms relapse.  • 20-30% children with DS may require laxatives for several years.  

    Also laxatives are only half the story • Increase fibre content (to normal). • Ensure adequate hydration • Increase exercise levels (all evidence based). 

  • Positive behavioural interventions/rewards suited to the child’s level.  • Explain that treatment may take years.  • Addressing the underlying trigger – Understanding of parents – Fear of toilets in younger children – Access to school toilets in school age children.  • Early reassessment and reinforcement of initial messages is also key. 

  • Other resources: Social stories/school nurse/health visitor/continence nurse and www.eric.org.uk and Free helpline: 0808 169 9949

Toileting guidance:

https://www.bbuk.org.uk/wp-content/uploads/2019/08/Top-tips-for-potty-training.pdf

Screening for Coeliac Disease in Children with Down Syndrome

Why Testing is Important:
Children with Down Syndrome are at higher risk of developing coeliac disease (CD), which, if untreated, can lead to serious complications, including:

  • Malabsorption: Poor nutrient absorption causing iron deficiency anaemia, vitamin B12 or folate deficiency anaemia, and osteoporosis.

  • Malnutrition: Severe nutrient deficiency causing fatigue, dizziness, and, in children, stunted growth. Treatment involves a high-calorie diet and supplements.

  • Lactose Intolerance: Temporary lactose intolerance from gut damage, leading to bloating and discomfort, usually resolving with a gluten-free diet.

  • Cancer (Rare): A slight increase in the risk of small bowel cancer, small bowel lymphoma, and Hodgkin lymphoma, which normalises on a gluten-free diet.

Coeliac Disease and Associated Conditions:

  • Coeliac Disease and Type 1 Diabetes: CD is more common in individuals with type 1 diabetes due to their shared autoimmune origin. Silent CD, without symptoms, is diagnosed only through routine screening. Screening for diabetes is also essential if symptoms such as increased thirst, frequent urination, or unexplained weight loss occur. There is no link between CD and type 2 diabetes.

  • Coeliac Disease and CK/Transaminase Levels: Elevated creatine phosphokinase (CK) levels, found in 40% of children with CD, can indicate CD, especially with gastrointestinal symptoms. CK levels typically return to normal with a gluten-free diet. Elevated transaminase levels (HT) are also a recognised marker of CD.

Current UK Guidance:
The UK recommends a low threshold for testing children with Down Syndrome for CD, using:

  • Blood test for Coeliac antibodies (TTG)

  • Total immunoglobulin A (IgA) (to detect IgA deficiency, which may cause false negatives)

Local Consensus in Barnet:

  • Symptomatic children: Immediate TTG testing (e.g., loose stools, constipation, abdominal discomfort).

  • Asymptomatic children: Routine TTG testing every 3 years.

  • HLA Testing: Offered locally to identify genetic susceptibility to CD without the need for gluten intake. Complete the HLA test using this form.

Understanding HLA Testing:

  • HLA Positive (DQ2 or DQ8): Indicates genetic potential for CD, requiring periodic screening.

  • HLA Negative: Virtually excludes CD, removing the need for future routine TTG testing.

When to Test:

  • TTG/EMA accuracy depends on regular gluten intake before testing.

  • Diagnosis without a biopsy is possible if TTG is ≥10 times the normal limit and EMA is positive on a second sample.

Next Steps for Positive Results:

  • Refer to a paediatric gastroenterologist.

  • Do not start a gluten-free diet before specialist consultation to ensure diagnostic accuracy.