Small Bowel and Large Bowel transit
During the clinical evaluation of suspected motility disorders, it can often be difficult to determine whether a patient’s symptoms are due to an upper or a lower tract disorder. Therefore, at Trinity Medical Imaging we can perform a complete gastrointestinal transit study which allows us to assess gastric emptying, small bowel transit and colonic transit in one examination.
The study relies on taking different radiopharmaceuticals orally which have different physical radioactive properties. This way a delay in transit in one part of the gastrointestinal tract does not interfere with the results from the rest of the system.
SeHCAT studies are used to diagnose bile acid malabsorption associated chronic diarrhoea.
Unlike other centres, the technique at Trinity Medical Imaging is accurate, reproducible and conforms to international standards.
During the study, patients are asked to eat a meal of scrambled eggs and either water or a capsule with a delayed release of radioactivity. Images are taken for up to 6 hours on the first day of the scan, and then the patient will return daily for a scan up to four days later.
With this technique, we can not only confirm or exclude a motility disorder, but we can determine where in the gastrointestinal tract the delay is occurring.
Whole gut transit studies can evaluate gastric emptying, small bowel transit and colonic transit in patients with chronic constipation. It is essential to confirm slow transit constipation especially in patients considered for surgery.
SeHCAT Bile Salt Absorption
Bile acid malabsorption has been identified as a potential cause of diarrhoea predominant irritable bowel syndrome for many years. Yet it remains an under-recognised and underdiagnosed condition.
Bile salts synthesized in the liver are usually reasbsorbed in the terminal ileum and returned to the liver for recycling. Conditions that interrupt this enterohepatic circulation, such as ileal resection, Crohn’s disease or disrupted feedback control of bile acid synthesis, lead to bile salts spilling into the colon where they cause watery stools, urgency and faecal incontinence.
SeHCAT tests utilise a very low dose of a radioactive isotope that is bound to an analogue of a naturally occuring bile acid. The radiopharmaceutical is taken orally in a form of a capsule and two measurements of the radioactivity are taken; one on the first day of the test and after one week.
The test is non-invasive and does not require blood tests or injections.
The information from this test allows the doctor to confirm or exclude the presence of bile acid malabsorption.