This study is checking if a medicine called tradipitant is safe and helps with gastroparesis, a stomach condition where food moves too slowly. The study compares tradipitant to a placebo, a harmless pill with no medicine. Eligible participants include those diagnosed with gastroparesis, experiencing delayed gastric emptying (where food takes too long to leave the stomach), and moderate to severe nausea. Participants should have a Body Mass Index (BMI), which is a measure of body fat based on height and weight, between 18 and 40. Some conditions may exclude participation, such as having other disorders that cause similar symptoms, recent use of certain medicines, or recent stomach surgeries. Key points to consider include:

• Participants must visit the study site for evaluations.
• Participants may receive compensation for their time and travel.
• Potential risks include side effects from tradipitant, such as headache or dizziness.