Participant Inclusion Criteria--
Functional Dyspepsia Group:
- Males and females; ages 18-65 years
- Rome V functional dyspepsia post-prandial distress syndrome subtype
- Negative upper endoscopy or upper GI series to rule out structural/organic cause for FD
- greater than or equal to 5.5 gut interoceptive awareness score (by VSI awareness subscale)
- Fluent in English
- Willing and able to provide informed consent
- Stable dose for 30 days prior to Visit 1 if on a neuropsychiatric medication (e.g., TCA, SNRI, SSRI mirtazapine, atypical antipsychotic, gabapentin, buspirone, pregabalin)
- No current plans to initiate a new or change dosing on a neuropsychiatric medication within the study period
Anorexia Nervosa Group:
- Males and females; ages 18-65 years
- DSM-5 anorexia restricting-type by the Eating Disorder Module in the Diagnostic Interview for Mood, Anxiety, and OCD and related Neuropsychiatric Disorders (DIAMOND)
- greater than or equal to 5.5 gut interoceptive awareness score (by VSI awareness subscale)
- Fluent in English
- Willing and able to provide informed consent
- Stable dose for 30 days prior to Visit 1 if on an SSRI
- No current plans to initiate a new neuromodulator
- No current plans to initiate a new SSRI or change dosing on an SSRI
Healthy Controls:
- Males and females; ages 18-65 years
- BMI greater than or equal to 18.5 kg/m2
- Fluent in English
- Willing and able to provide informed consent
Participant Exclusion Criteria--
Functional Dyspepsia Group:
Presence of other conditions that could explain the patient's symptoms by medical chart:
- Pyloric or intestinal obstruction (by EGD, UGI, or Abdominal CT)
- Active H.pylori (by CLO test or stool antigen test)
- Active inflammatory bowel disease
- Eosinophilic gastroenteritis or eosinophilic esophagitis
- Acute renal failure
- Chronic renal failure (serum creatinine >3 mg/dL) and/or on hemodialysis or peritoneal dialysis
- Acute liver failure
- Any acute gastrointestinal process
- Any plausible structural or metabolic causes
- Heartburn as predominant symptom
- History of peptic ulcer
Symptom resolution with antisecretory therapy (PPI use for other reasons that did not resolve FD symptoms will be allowed)
Endorses any contraindications to MRI
Body weight of 450 lbs or greater or BMI of 50 kg/m2 or greater (limit of MRI table)
Allergy to pineapple (used in the test meal during MRI)
History of GI tract surgery or any serious medical condition (e.g., cancer)
Pregnancy/breastfeeding within the last 8 weeks
Uncontrolled diabetes (indicated by HbA1c greater than or equal to 7%) by chart
Narcotic analgesics greater than three days per week
Cannabinoid use greater than three days per week
Intellectual disability by history
Illiteracy
History of weight/shape-based eating disorder including anorexia nervosa by DIAMOND
Current binge eating by DIAMOND
Current self-induced vomiting by DIAMOND
Current laxative or diuretic misuse by DIAMOND
Current substance/alcohol use disorder within past year by DIAMOND
Current/history of psychosis by DIAMOND
Current mania by DIAMOND
Active suicidal ideation by modified DIAMOND abbreviated suicide module; passive suicidal ideation is allowed
Inability or unwillingness to consume food by mouth
Inability to provide informed consent
Anorexia Nervosa Group:
- Diagnosis of chronic gastrointestinal disorder
- Rome V functional dyspepsia
- Endorses any contraindications to MRI
- Body weight of 450 lbs or greater or BMI of 50 kg/m2 or greater (limit of MRI table)
- Allergy to pineapple (used in the test meal during MRI)
- History of GI tract surgery or any serious medical condition (e.g., cancer)
- Pregnancy/breastfeeding within the last 8 weeks
- Uncontrolled diabetes (indicated by HbA1c greater than or equal to 7%) by chart
- Narcotic analgesics greater than three days per week
- Cannabinoid use greater than three days per week
- Intellectual disability by history
- Illiteracy
- Current binge eating by DIAMOND
- Current self-induced vomiting by DIAMOND
- Current laxative or diuretic misuse by DIAMOND
- Current substance/alcohol use disorder within past year by DIAMOND
- Current/history of psychosis by DIAMOND
- Current mania by DIAMOND
- Active suicidal ideation by DIAMOND abbreviated suicide module; passive suicidal ideation is allowed
- Inability or unwillingness to consume food by mouth
- Inability to provide informed consent
- Current use of neuropsychiatric medication other than an SSRI (e.g., TCA, SNRI, mirtazapine, atypical antipsychotic, gabapentin, buspirone, pregabalin)
Healthy Controls:
- Diagnosis of chronic gastrointestinal or pain disorder
- Rome V functional dyspepsia
- greater than or equal to 5.5 gut interoceptive awareness score (by VSI awareness subscale)
- Current use of a medication known to influence gastric sensorimotor functions (including neuromodulators and SSRIs)
- Active psychiatric disorder including a feeding/eating disorder by DIAMOND
- Endorses any contraindications to MRI
- Body weight of 450 lbs or greater or BMI of 50 kg/m2 or greater (limit of MRI table)
- Allergy to pineapple (used in the test meal during MRI)
- History of GI tract surgery or any serious medical condition (e.g., cancer)
- Pregnancy/breastfeeding within the last 8 weeks
- Uncontrolled diabetes (indicated by HbA1c greater than or equal to 7%) by chart
- Narcotic analgesics greater than three days per week
- Cannabinoid use greater than three days per week
- Intellectual disability by history
- Illiteracy
- Current binge eating by DIAMOND
- Current self-induced vomiting by DIAMOND
- Current laxative or diuretic misuse by DIAMOND
- Current substance/alcohol use disorder within past year by DIAMOND
- Current/history of psychosis by DIAMOND
- Current mania by DIAMOND
- Active suicidal ideation by DIAMOND modified suicide module; passive suicidal ideation is allowed
- Inability or unwillingness to consume food by mouth
- Inability to provide informed consent