The study objective is to demonstrate the equivalence of the Atmo Motility Gas Capsule System with the predicate SmartPill in measuring gastric emptying time and colonic transit time through examination of device agreement.

The clinical protocol for the study is designed to compare the performance of the Atmo Motility Gas Capsule System to the predicate device, the SmartPill GI Monitoring System, in patients with chronic GI symptoms suggestive of GI motility disorders (specifically gastroparesis and slow transit constipation), in order to demonstrate substantial equivalence. This study will involve the recruitment of symptomatic participants from a population that is representative of that for which the device is intended.

The primary objective of this study is the assessment of the agreement of Atmo Motility and SmartPill Systems' results with regards to both GET and CTT. The SmartPill is the accepted gold standard test for GI motility transit time analysis. Device agreement will be primarily examined through Bland-Altman analyses for GET and CTT measurements from the Atmo Motility and SmartPill Systems.

Inclusion Criteria:

1. Adults (M/F/other) between the ages of 22-80 years of age

2. High probability of compliance and completion of study.

3. Fulfilling one or more of the following criteria:

   A. Received a delayed gastric emptying result from a gastric emptying study (gastric scintigraphy [GES] or gastric emptying breath test [GEBT] or SmartPill) in the last two years AND/OR presenting with 2 or more of the following symptoms or signs: i. Nausea, vomiting, or retching (dry heaves) ii. Postprandial fullness or early satiety iii. Bloating or visible abdominal distention iv. Postprandial discomfort or pain AND/OR; B. Suffering from symptoms of chronic idiopathic constipation based on ROME IV criteria (exclusion of constipation caused by structural abnormalities), participant should have at least 1 bowel motion per week (either assisted or unassisted by medication) AND/OR; C. Suffering from symptoms of IBS-C based on ROME IV criteria

4. Participant or their legally authorized representative has the ability to provide informed consent and comply with the protocol.

Exclusion Criteria:

1. Recent abdominal and/or pelvic surgery (past 3 months)
2. Acute diverticulitis, confirmed by CT scan in past 3 months, diverticular stricture, and other intestinal strictures
3. Chronic daily use of nonsteroidal anti-inflammatory drugs (e.g. ibuprofen, naproxen)
4. Pregnant or breastfeeding
5. Patients on long-acting glucagon-like peptide (GLP-1)
6. Active implantable devices (e.g. gastric stimulator, pacemaker, defibrillator) [continuous glucose monitors are permitted]
7. Evidence of metabolic disease within the last six months (overt hypothyroidism [high TSH, low FT4], uncontrolled diabetes [hemoglobin A1c >10%] within the past 6 months) not stabilized within the past 3 months via constant medication (dosage and type must be consistent) usage
8. History of gastric bezoar formation
9. Presence of fistulas or other mechanical GI obstruction
10. Radiation enteritis
11. History of fecal impaction
12. Suspicion of other organic GI disease
13. Suspicion of obscure GI bleeding
14. Unable to stop medications that may alter gastric pH (such as proton pump inhibitors) for 7 days prior to and during study
15. Unable to stop medications that may alter GI motility (GLP-1 agonists, anticholinergics, metformin, antispasmodic, prokinetics) for 72 hours prior to and during study.
16. Chronic daily use of cannabinoids (e.g., dronabinol, marijuana)
17. Unable to stop laxatives (docusate, lactulose, sorbitol, senna, bisacodyl), suppositories (glycerin), and enema 72 hours prior to and during the study. Limited use of rescue laxatives is permissible at the investigators discretion but must be tracked in the electronic case report form (eCRF).
18. May require an MRI scan during the duration of this study
19. BMI > 40kg/m2
20. Allergies to any of the ingredients used in the standardized meal