A 28-year-old graduate student complains of chronic heartburn that intensifies when lying in bed. The condition became prevalent during his qualifying exams five years previously and has recurred as he is approaching his final thesis defense. The patient had been taking omeprazole (Prilosec^TM) to manage the symptoms of acid reflux.

The doctor first asks the patient to wean off of the proton pump inhibitor (Prilosec^TM), but the patient reports that previous attempts led to recurrence of heartburn when he went to bed. She decides to run tests to determine the source of the reflux and first orders upper GI radiography (barium swallow).

1. What tissue layers make up the wall of the stomach (start list with layer adjacent to the lumen)?

2. How does a drug like omeprazole work. Why is that different from an antacid like Tums(TM)? (Please do not write your answer like a commercial for these drugs, stick to scientific explanations.)

3. What is the risk of chronic acid reflux?

4. If the barium swallow is inconclusive, what is another test that can be ordered that will look for evidence of abnormal growths (polyps) in the upper GI tract?