Patient case (clinical description): A 48-year-old man comes to the office complaining of heartburn and acid reflux.  He has taken over-the-counter antacids but sees no relief.  Other medical history is unremarkable.  The patient does not use tobacco, alcohol, or illicit drugs.  Vital signs are within normal limits.  BMI is 31 kg/m2.  Physical examination is  positive for mild tenderness in upper stomach. Chest x-ray shows an air-fluid opacity behind the heart.  A barium swallow study reveals approximately 1/3 of the stomach herniating through the esophageal hiatus.

Patient's own account: I went to my doctor's office because of a non-stop heartburn and some acid reflux. I took over-the-counter medications, but it keeps going strong! I don't smoke, take drugs or drink alcohol, I'm healthy! The doctor took my vitals, which turned out normal. My BMI is 31, which might be a bit too much for a 48-year-old guy like me. They examined my stomach and found a mild tenderness in the upper part. I also did some X-rays, and they found out that I have an air-fluid opacity behind my heart. I did another X-ray, and it turns out that a part of my stomach went up my chest through a hole in my diaphragm!

Clinical trial: Clinical Trial to Assess the Efficacy and Safety of YYD601 in the Treatment of Esophageal Reflux Disease (ERD)

Eligibility criteria:
Inclusion Criteria:

          -  A man or woman over 20 years old less than 70 years old.

          -  A man or woman who has experienced symptom (heartburn and acid regurgitation) within 7
             days before Visit 1, meet below 1) or 2) criteria, who has been made diagnosis as
             Erosive esophagitis(LA grade A~D) measured through the endoscopy which is carried out
             within (-2W±D2)

             * Symptom (heartburn and acid regurgitation) is confirmed by RDQ.

               1. Experienced above 2 days in 1 week, Heartburn of acid regurgitation above the
                  weakness.

               2. Experienced above 1 day in 1 week, Heartburn of acid regurgitation above the
                  middle.

          -  A man or woman who has a full understanding of this clinical trial through the
             detailed explanation, agree in writing to participate in this trial.

        Exclusion Criteria:

          -  Who has hyper sensitivity reaction about other drugs, ingredients, components of
             investigator product or compound of benzimidazole.

          -  Who has NERD

          -  Who get a diagnosis as a IBS within the last 3 months.

          -  Who have taken gastric acid secretion inhibitors including PPIs within 2 weeks before
             the endoscopy.

          -  Who have taken drugs about reflux esophagitis (H₂-receptor inhibitor (H2RA)
             Prostaglandin(PG), Antacid, Prokinetic acid etc.) above 2 times as an usual dose. (*
             refer to the Concomitant medication in text.)

          -  Who has been experienced the disease affecting the esophagus(Eosinophilic esophagitis,
             esophageal varices, cirrhosis, Virus or Fungal infection, Esophageal stricture,
             primary esophageal motility disorder and gastrointestinal bleeding). Or who has a
             history of radio therapeutics, freeze treatment about the esophagus.

          -  Who has clinically significant abnormal result of ECG.

          -  Abnormal result of Major arrhythmia, Multifocal PVS, 2 AV-blcok etc.

          -  Who has the Schatzki near the LES(lower esophageal sphincter) except the Barret's
             esophagus.
No condition on gender to be admitted to the trial.
No healthy subjects accepted to join the trial.
Subject must be at least 20 Years old.
Subject must be at most 70 Years

Eligibility (NLI label): Contradiction