This prospective, double-blinded, randomized, multicenter study will compare the efficacy and safety of two prokinetic regimens in patients with Rome IV-diagnosed functional dyspepsia. Ninety-two patients will be randomized (1:1) to receive either mosapride 5 mg + DA-9701 30 mg or mosapride 5 mg + matching placebo, three times daily before meals for 4 weeks. The primary endpoint is the proportion of overall responders ("much improved" or "very much improved" on a 7-point Likert scale) at Week 4. Secondary endpoints include overall response at Week 2, change in NDI-K symptom scores and PSQI-K sleep quality scores at Week 4, and safety assessments via laboratory tests and adverse-event monitoring.

A four-visit schedule: screening (Visit 1), randomization (Visit 2, same day), telephone follow-up at Week 2, and on-site assessment at Week 4. Screening includes informed consent, demographics, medical history, concomitant medications, labs, Rome IV questionnaire. Randomization uses opaque sealed envelopes generated by an independent statistician. Investigational products are dispensed in a double-dummy design to maintain blinding. Treatment compliance, vital signs, AEs collected at each contact. Efficacy via Likert scale, NDI-K, PSQI-K; safety via labs and AE reporting.

Inclusion Criteria:

1. ≥19 years of age

2. Patients diagnosed with functional dyspepsia according to the Rome IV criteria, who can be classified as having postprandial distress syndrome

   • Rome IV criteria for functional dyspepsia:

     1. One or more of the following symptoms:

        1. Uncomfortable postprandial fullness
        2. Early satiation
        3. Epigastric pain
        4. Epigastric burning

     2. No evidence of structural disease that could explain the symptoms

        • Symptoms must have started at least 6 months before diagnosis and been present during the last 3 months

3. No history of gastrointestinal surgery

4. No organic lesions found on upper endoscopy within the past 3 months

5. Voluntarily signed informed consent to participate in this clinical trial

Exclusion Criteria:

1. Patients with confirmed structural diseases on upper gastrointestinal endoscopy, such as esophageal stricture, ulcer stricture, esophagogastric varices, Barrett's esophagus, active peptic ulcer, gastrointestinal bleeding, or eosinophilic esophagitis

2. Patients who have undergone surgery involving the esophagus, stomach, or duodenum

3. Patients with abnormal values in blood chemistry tests within the past month:

   • Total bilirubin, creatinine > 1.5 times the upper limit of normal (ULN)
   • AST, ALT, alkaline phosphatase, BUN > 2 times the ULN

4. Patients with diabetic gastroparesis

5. Patients with a history of drug or alcohol abuse within the past year

6. Pregnant or breastfeeding women

   -Patients currently taking medications that may affect the evaluation of the investigational drug's efficacy (e.g., acid-suppressing agents including PPIs, prokinetics, NSAIDs, anticholinergics, corticosteroids, antidepressants, erythromycin, mirtazapine, etc.) may only participate after a minimum 2-week wash-out period

7. Any other conditions that the investigator deems make the patient unsuitable for participation in the study

Quadruple: Participant, Care Provider, Investigator, Outcomes Assessor - Double-blind with placebo tablets matched to DA-9701