Gastric Focused Ultrasound Stimulation

Inclusion Criteria:

* Age 18 to 70 years.
* Delayed gastric emptying or gastroparesis diagnosed by a clinician and confirmed by gastric emptying scintigraphy or a gastric emptying breath test.
* Ability to understand the study procedures, provide informed consent, and complete two study visits.
* Ability to consume the two bottles of Ensure or Glucerna nutritional drink used in the study.

Exclusion Criteria:

* Pregnancy.
* Epilepsy.
* Cardiac pacemaker or another implanted electronic medical device.
* Peritoneal dialysis.
* Daily use of narcotic or opioid medications.
* Abdominal wall ulcers, open wounds, active infection, or significant skin irritation in the area where the electrogastrography electrodes or focused ultrasound transducer will be placed.
* Known allergy or contraindication to the available Ensure or Glucerna nutritional drinks.
* Any other medical or safety condition that, in the judgment of the study team, would make participation unsafe.

Medication Restrictions:

Participants using medications that may significantly affect gastric motility or gastric emptying may be rescheduled if those medications were used within the study-defined restriction period. Relevant medications include opioid analgesics, prokinetic agents, anticholinergic or antispasmodic agents, GLP-1 receptor agonists or related medications, and anti-nausea or antiemetic medications that may affect gastrointestinal function. Participants should not discontinue any medically necessary medication without first consulting their treating physician.