Gastrointestinal motility refers to the contractile actions in the gut that serve to mix our food and propel it through out digestive tract. Although known to be involved in a range of conditions like chronic constipation, Parkinson's and Crohn's disease, investigator have never had effective tests with which to study the process. Advances in medical imaging technologies now make it possible to both see and quantify this process non-invasively using MRI. In this study the investigator first of all validate that our MRI based analysis is robust and valid, producing predictable results against range of known stimuli. The investigator then apply the technique to a cohort of participants with Chronic Intestinal Pseudo-Obstruction. These participants are known to have hypo-motile small bowels and demonstration with our MRI technique would serve as further validation. The investigator also investigate two cohorts of people with and without gastrointestinal diseases to better understand how the technique may work in the clinical setting.