Inclusion Criteria:  Diagnosed with gastroparesis (idiopathic or diabetic) for at least 12 weeks (based on scintigraphy results) and able to eat orally. Diagnosed with slow transit constipation for at least 12 weeks (exclusion of constipation caused by structural abnormalities with colonoscopy, and confirmation of slow transit by 'marker studies' such as scintigraphy, radiolabelled or opaque X-ray study). Participant would have at least 1 bowel motion per week (either assisted or unassisted by medication). No evidence of metabolic disease (hypothyroidism, uncontrolled diabetes [hemoglobin A1c >10% within the past 6 months], electrolyte imbalance). An endoscopy or gastrointestinal barium series within the past 3 years showing no organic disease that is potentially causative of symptoms. Ability to stop medications that may alter gastric pH (such as proton pump inhibitors) for 3 days prior to and during study. Ability to stop medications that may alter gastrointestinal motility (GLP-1 angonists, anticholinergics, cannabinoids, metformin, antispasmodic, prokinetics) for 3 days prior to and during study. Ability to stop antibiotic, probiotic and, prebiotic supplements 7 days before prior to and during study. Ability to stop laxatives (docusate, lactulose, sorbitol, senna, bisacodyl), suppositories (glycerin), and enema 3 days prior to and during the study. Does not require a MRI scan during the duration of this study  Exclusion Criteria:  Previous abdominal and/or pelvic surgery History of diverticulitis, diverticular stricture, and other intestinal strictures Chronic daily use of nonsteroidal anti-inflammatory drugs (ibuprofen, naproxen, etc.) Pregnant or nursing Patients on long-acting glucagon-like peptide (GLP-1) Implantable devices (e.g. pacemaker, defibrillator) [continuous glucose monitors are permitted]. History of bezoar formation Dysphagia to solid foods Gastric/jejunal feeding tubes