MRI and Microbiota Analysis in Constipation

Validation of Magnetic Resonance Imaging to Characterise Gastrointestinal Physiology, Gut Luminal Content and Its Interaction With Colonic Microbiota in Patients With Chronic Constipation

The purpose of the study is to test how well magnetic resonance imaging (MRI) can measure whole gut transit time in people with constipation, and how readily it can detect a change in transit time induced by taking a dietary supplement with laxative effects.The investigators expect to demonstrate that ispaghula (psyllium) accelerates movement of matter through the intestinal tract.

The investigators will also assess whether a change in gut bacteria and the chemicals that they release can be detected.

Inclusion Criteria:

• Meets Rome III Criteria for diagnosis of Functional Constipation5 on questionnaire (NB. Both those who do and do not meet IBS criteria will be eligible)
• At least one bowel motion per week while taking usual laxatives
• Able to give informed consent
• Aged 18 or older

Exclusion Criteria:

• History declared by the candidate of other pre-existing gastrointestinal disorder, including but not limited to:
• Inflammatory Bowel Disease
• Coeliac Disease diagnosed in the last year
• Pancreatitis
• Cancer of the gastrointestinal tract
• Any reported history of gastrointestinal resection (excluding appendicectomy or cholecystectomy)
• Presence of an intestinal stoma
• Pregnancy declared by candidate (no formal testing)
• Contraindications for MRI scanning i.e. metallic implants, pacemakers, history of metallic foreign body in eye(s) and penetrating eye injury
• Reported alcohol intake of >28 units/ week with daily drinking
• Any use of a product containing ispaghula or psyllium in the 4 weeks prior to consent
• Unable to avoid use of dihydrocodeine or morphine during the study
• If taking other regular opiates such as codeine, fentanyl or Oxycodone, participants should be able to maintain a stable dose throughout the study
• Any reported history of hypersensitivity or significant adverse reaction to ispaghula, maltodextrin or bisacodyl
• Unable to stop drugs and other agents used primarily for their laxative effect, during periods of screening, washout, baseline and treatment (maximum 15 days - rescue medication will be provided).
• Antibiotic or prescribed probiotic treatment in the past 4 weeks
• Inability to lie flat or exceed scanner limits of weight <120kg
• Poor understanding of English language
• Participation in any medical trials for the past 3 months
• Any condition where the candidate is likely to require a course of antibiotics in the next 3 months e.g. severe chronic respiratory disease, recurrent urinary tract infection, lower limb ulceration
• Judgement by the PI that the candidate who will be unable to comply with the full study protocol e.g. Diabetes, severe COPD

During the screening 2 weeks off laxatives

• No bowel motions recorded during screening period
• ≥3 complete spontaneous bowel motions (CSBMs - bowel motion with the feeling of complete evacuation, without the use of rescue therapy in the preceding 24 hours) per week