Serum Gastric Acid Secretion Test (Quantitative, 24-Hour Collection)

Why This Test Is Done

Your doctor may recommend this test if you have symptoms like persistent heartburn, nausea, diarrhea, or unexplained weight loss. It’s also used to check for rare conditions that cause unusually high stomach acid levels, such as tumors or other disorders affecting digestion.

How the Test Works

You’ll collect urine samples for 24 hours, which contain markers of stomach acid production. The test measures these markers to estimate total acid output. Special urine collection devices help track timing accurately.

Sample Collection Process

You’ll receive instructions to collect urine in a special container every time you urinate, including at night. Wear a bracelet or use a timer to mark the start/end time. Return the collected urine to the lab with the bracelet for verification.

What to Expect Before the Test

Avoid certain medications (like proton pump inhibitors) that can affect acid levels. Follow your doctor’s instructions for diet, hydration, and timing to ensure accurate results.