Small and Large Bowel Transit Tests Using MRI (Study 1)
Condition: Irritable Bowel Syndrome
MeSH terms: Irritable Bowel Syndrome
Study type: Observational

Summary: 
      Irritable bowel syndrome, (IBS) is a common functional disorder of the gut that can be quite
      disabling to patients. The most common symptoms of IBS are abdominal pain or discomfort along
      with erratic changes in bowel habit of diarrhoea, constipation or a mixture of the two
      (referred to as IBS subtypes). Despite much research efforts to further understand the
      pathophysiology of IBS; as yet no specific biomarkers/definitive measurements have been
      identified that can be use to aid the diagnosis and reduce the need for unnecessary,
      unpleasant and expensive tests.

      Evidence shows that anxiety plays a part in IBS and can speed up transit time in the small
      bowel. In this study, the investigators hypothesise that since anxiety is a common feature of
      IBS, then fast small bowel transit is likely to be found in all subtypes of IBS and the
      difference in stool frequency and consistency in IBS subgroups are therefore likely to
      reflect differences in colonic function. The investigator wish to test this by measuring both
      small and large bowel transit times using Magnetic Resonance Imaging (MRI) and validate the
      results of the MRI with two methods currently used in clinical practice -The previously
      validated lactose-C13 Ureide breath test (for small bowel transit) and the standard
      radio-opaque pellet method to assess the whole gut transit (WGT) time.
    

Detailed description: 
      The investigator has 2 main parts in this study i.e. Study 1 and Study 2.

      As part of study 1, the investigator would like to recruit up to 5 healthy volunteers as a
      pilot study to optimise measurement and analysis of the Lactose-C13 Ureide breath test along
      with MRI scannings at regular intervals.

      Following from this, the investigator would like assess the feasibility and reproducibility
      of using MRI imaging to assess gastrointestinal transit. The investigator would like to
      recruit 21 healthy volunteers to measure orocaecal transit time (OCTT) and whole gut
      transit(WGT)using the conventional method of Lactose-C13 Ureide breath test for OCTT and the
      Metcalf method using standard radio-opaque pellet method for WGT and compare them will MRI
      imaging. Once this has been analysed and the best method for each OCTT and WGT have been
      decided, these methods would be applied in Study 2.

      In study 2, the investigator would like to recruit 30 healthy volunteers, 30 patients with
      diarrhoea predominantly Irritable Bowel Syndrome, 30 patients with constipation predominantly
      Irritable Bowel Syndrome and 30 patients with Mixed irritable Bowel Syndrome. The best
      methods from study 1 for OCTT and WGT will be applied here to assess gastrointestinal transit
      on these subjects. Based on the first study, the best method to assess OCTT is the
      Lactose-C13 Ureide breath test and for the WGT, the best method is the MRI marker capsules.
      Participants will need to fill in questionnaires to assess their stress levels and to fill in
      symptom questionnaires during the study day.
    

Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Healthy volunteers will be selected via poster advertisement Participants with Irritable
        Bowel Syndrome will be selected from the gastroenterology clinics /poster advertisement
      
Biospecimen description: 
      Study 1: no samples Study 2: no samples