Assessment of Gastro-Intestinal Function to a Mixed Meal by Non-invasive Imaging

Inclusion Criteria: 1. Be an adult patient above 18 years old 2. Have a body mass index of \>18 and \<30kg.m2 and not exceed a waist circumference of 99cm at 5cm above ileal crest 3. Be able to give voluntary informed consent and from whom written consent to participate has been obtained. 4. Be able to understand the study, willing to co-operate with the study procedures and able to attend all study assessments. 5. Be willing to abstain from alcohol for 24 hours before and during the imaging appointment. 6. Be willing to fast from midnight prior to the screening and imaging appointment 7. Be able to ingest at least 400ml nutrient liquid (0.75kcal/ml at 40ml/min) during a Nutrient Drinking Test without experiencing more than moderate dyspeptic symptoms (no such restriction for patients with dyspeptic symptoms) 8. Be able to swallow a solid agar bead between 7.5 and 11.5 mm in diameter 9. Be willing to consent to their General Practitioner (GP) being informed of their participation. Exclusion Criteria: 1. Have a history of gastrointestinal disease or surgery (other than appendicitis or hysterectomy) 2. Have ongoing disease requiring active management (including impaired renal clearance GFR \<50 mL/min/1.73 m2) 3. Have a documented history of alcohol or drug abuse 4. Fail to satisfy the investigator's assessment of fitness to participate based on a survey of inclusion and exclusion criteria 5. Have consumed alcohol within 24 hours of start of study 6. Have participated in a similar study involving the use of radioisotopes in the previous 3 months such that participating in the current study would exceed the recommended yearly exposure limit (5mSv) 7. Take any medication which may affect oesophageal or gastric motility for a minimum 7 days 8. Have had previous history of gastric surgery 9. Have active upper gastrointestinal diseases 10. Have an active Eating Disorder 11. Have an allergy to milk protein (milk based, lactose free test meal) 12. Be a vegan 13. Be pregnant or breastfeeding 14. Have any contraindication to MRI scanning according to local guidelines