CompletedObservational

BioEvocs - Testing the 'poo sniffer' in children and young people with eosinophilic esophagitis

Eosinophilic oesophagitis (EoE) is an illness where the food pipe (gullet) becomes inflamed, causing swallowing problems, food getting stuck, and painful reflux. Currently, doctors must put children to sleep under general anaesthetic for an endoscopy camera test to see if treatments are working. The BioEvocs study tests a gentler approach: checking stool samples. Stool gives off tiny scent particles called volatile gases, produced by gut bacteria and digestion. When the gut is inflamed, these gases can change. Researchers want to see if analysing these gases in a laboratory can show whether EoE is active and if treatments are helping. Children with EoE, as well as children attending hospital for other reasons, simply provide a stool sample. If successful, this research could help reduce the need for repeated camera tests under anaesthetic for young people in the future.

At a glance

Status

Completed

Sponsor

Alder Hey Children's Hospital

Enrolment target

120

Start

13 Dec 2023

Estimated completion

30 Sep 2025

Eosinophilic esophagitis

What is this study about?

Eosinophilic oesophagitis (EoE) is a long-term condition that makes the lining of the food pipe (gullet) red and swollen. Children and young people with EoE often find it hard or painful to swallow food, experience severe acid reflux, or find that food gets stuck in their chest. Currently, the only reliable way to check this inflammation is an endoscopy. This involves passing a tiny camera down the food pipe while the child is fully asleep under a general anaesthetic. Because doctors need to check whether changes in medicines or diets are working, children often have to undergo multiple camera tests over time.

Medical teams want to find an easier, painless test that does not require a hospital admission or general anaesthetic. This research study looks at a new tool nicknamed the 'poo sniffer'. Stool naturally gives off microscopic gases, known as volatile organic compounds, which create its smell. These gases are shaped by the foods we eat, our gut bacteria, and swelling or irritation anywhere in the digestive system.

By measuring these gases using specialist laboratory equipment, scientists want to see if they can detect clear patterns linked to active EoE. If the method works, doctors could one day check how well a child's treatment is working just by testing a simple stool sample. While this study is an early research step, it has the potential to make future care much gentler and far less stressful for young people.

Key takeaways

Researchers are testing whether gases in stool can reveal inflammation caused by eosinophilic oesophagitis (EoE).
The goal is to discover if simple stool tests could eventually reduce the need for camera tests under general anaesthetic.
Participation involves collecting and donating a single stool sample during routine hospital care.
The study includes young people with EoE, as well as comparison groups with other conditions or no gut problems.
Taking part will not change your current NHS treatment or planned medical tests.

Who may be eligible?

The study is looking for children and young people who have a confirmed diagnosis of eosinophilic oesophagitis (EoE), those having investigations for a flare-up of symptoms, and those waiting to start EoE treatment. To compare the results accurately, the study also welcomes 'control' participants. These are children visiting hospital clinics for other food pipe conditions, or children attending eye clinics who have no digestive problems at all.

To be eligible, the young person must be able to provide a stool sample, and both the child and their parents or guardians must give informed consent to take part.

Children cannot take part if they have had surgery to remove part of their large bowel (colon), or if they take a special elemental liquid diet for reasons other than EoE. Those who have taken antibiotics within the last four weeks, or who have chronic bowel infections, long-term diarrhoea, or irritable bowel syndrome (IBS), are also excluded because these factors change the gases found in stool.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

The participant is a child or young person under the care of a participating NHS hospital.
The participant has known or suspected EoE, or has been invited as a clinic control.
The participant can provide a stool sample.
The participant has not taken antibiotics in the last 4 weeks.
The participant has not had surgery to remove part of the large bowel.
The participant does not have irritable bowel syndrome (IBS) or long-term chronic diarrhoea.

Answer every question to see your result.

What does participation involve?

Taking part in this study is very straightforward and will not disrupt your regular healthcare. If you agree to take part, you will be given a collection kit to provide a single stool sample. This can usually be handed in during a routine hospital appointment or clinic visit. There are no study medications to take, no extra scans, and no blood tests involved. The sample is sent to a laboratory, where researchers will measure the gases it releases. The study is running until March 2026 across several children's hospitals in the UK, including Alder Hey, Great Ormond Street, Chelsea and Westminster, Sheffield, and Newcastle. Your usual treatments, clinic reviews, and planned endoscopies will go ahead exactly as planned.

Potential risks and benefits

There are no physical risks or painful procedures involved in providing a stool sample. Taking part will not directly change your personal treatment or diagnosis, as samples are tested in batches for research rather than for immediate clinical decisions. However, your involvement could help researchers develop a non-invasive test that spares other children from having repeated camera tests under anaesthetic in the future. Taking part is entirely voluntary, and you can withdraw from the study at any point without it affecting your NHS medical care.

Locations (5)

Some site locations are approximate. We're improving this — please verify with the trial team before travelling.

Alderhey
City only
Liverpool, England
Great Ormond Street Hospital Central London Site
City only
London, England
Chelsea and Westminster Hospital NHS Foundation Trust
City only
London, England
Sheffield Childrens Hospital
City only
Sheffield, England
The Royal Victoria Infirmary and Associated Hospitals NHS Trust
City only
Newcastle upon Tyne, England

Common questions

What is the 'poo sniffer' test?

It is a laboratory machine that measures tiny gases (volatile organic compounds) released by stool. These gases change when the digestive system is irritated or inflamed.

Will taking part replace my planned endoscopy?

No. The stool test is still being researched, so any scheduled camera tests or regular medical care will continue exactly as recommended by your doctor.

How do we collect the stool sample?

The research team will give you a clean, simple collection kit with clear instructions on how to collect the sample at home or during your hospital visit.

Do I have to pay to take part?

No. There is no cost to take part in this NHS-supported study, and you will not receive payment for providing a sample.

Can I leave the study if I change my mind?

Yes, you or your child can withdraw at any time without giving a reason, and it will not affect your standard NHS treatment in any way.

How to find out more

Marcus Auth

mkh.auth@alderhey.nhs.uk +44 (0)1512284811 Official trial record

Always speak to your GP or specialist before deciding to take part in a study.