Chronic Nausea and Vomiting in Patients With Normal Gastric Emptying Using the Enterra® Therapy System (NAVIGATE)

Inclusion Criteria:

* Willing and able to complete the informed consent process
* Stated willingness to comply with all study procedures and availability for the duration of the study
* Aged ≥18 years at time of informed consent
* Chronic, drug-refractory nausea that: a) has been present for more than 6 months, and b) has been active within the last 3 months prior to consent
* Patient is able to complete ANMS GCSI-DD surveys on a compatible smart device with: a) a minimum of four (4) ANMS GCSI-DD entries per week for two consecutive weeks, and b) an average ANMS GCSI-DD score for nausea severity of ≥2.5 during the same two-week period
* Refractory or intolerant to two or more of the following antiemetic drug classes: antihistamines, phenothiazines, serotonin type 3 receptor antagonists, dopamine type 2 receptor antagonists, anticholinergics, neurokinin receptor antagonists
* Medically stable, in the opinion of the investigator, during the month prior to consent, with no planned modifications to medical therapy during the course of the study
* Normal gastric emptying as assessed by a qualifying gastric emptying test performed within 2 years of consent if no prior pyloric transection therapy, or within 2 years of consent and after the most recent pyloric transection therapy
* Normal upper endoscopy within 1 year prior to consent (e.g., absence of obstructions, ulcers, or cancers in the esophagus, stomach, or duodenum) performed within 1 year of consent if no prior pyloric transection therapy, or within 1 year of consent and after the most recent pyloric transection therapy

Exclusion Criteria:

* Cognitive impairment or other characteristic that would limit a patient's ability to complete study requirements
* Pyloric transection therapy completed within 1 year of consent
* Documented gastrointestinal (GI) obstruction or pseudo-obstruction
* History of primary swallowing disorders
* History of primary psychogenic vomiting
* History of primary eating disorder
* History of cyclic vomiting syndrome
* History of rumination syndrome
* History of scleroderma
* History of amyloidosis
* History of cannabis hyperemesis syndrome
* Active H. pylori infection
* Evidence of bezoar during most recent endoscopy
* Previous gastric surgery of any type other than a pyloric transection therapy (i.e., pyloroplasty, pyloromyotomy, POP, or G-POEM)
* Uncontrolled thyroid disorder, in the opinion of the investigator
* History of seizures disorders
* Hemoglobin A1c \>8.0%
* Peritoneal dialysis or unstable hemodialysis
* Parenteral or enteral nutritional support
* Active pancreatitis
* History of organ transplant, gross malabsorptive syndromes, celiac disease, or inflammatory bowel disease
* Other GI tract diseases and disorders that the investigator believes may have caused the patient's drug-refractory nausea and/or vomiting
* Malignancy (with the exception of basal cell carcinoma of the skin) currently present, initially diagnosed or recurring within 5 years of consent
* Opioid use
* Current cannabis/cannabinoid use that exceeds: 3 days of usage per week, or 2 occurrences during each day of use, or 3 grams of total usage per week
* Heavy alcohol use, defined as: for men, consuming five or more drinks on any day or 15 or more per week; for women, consuming four or more drinks on any day or 8 or more per week
* Injection of Botox into the pyloric sphincter within 6 months of consent
* Active major levels of anxiety/depression, as determined by the investigator
* History of other clinically significant disease, or any other condition which, in the opinion of the Investigator, would jeopardize the safety of the patient or impact the validity of the study results
* Life expectancy \<1 year
* Pregnant or breastfeeding at the time of consent or intend to become pregnant during the study
* Any underlying disease leading to follow-up by MRI outside of current MR conditional indications
* Glucagon-like peptide 1 (GLP-1) agonist drug use within 6 months of consent
* Participation in other investigational clinical studies
* Existing or prior gastric electrical stimulator implantation