Gastro-oesophageal reflux is best detected by
**Core Concept**
Gastro-oesophageal reflux disease (GERD) is a condition characterized by the reflux of stomach acid into the oesophagus, leading to symptoms such as heartburn and regurgitation. The detection of GERD requires a diagnostic approach that can accurately identify the presence of acid reflux.
**Why the Correct Answer is Right**
Ambulatory 24-hour pH monitoring is considered the gold standard for detecting gastro-oesophageal reflux. This test measures the pH levels in the oesophagus over a 24-hour period, providing a comprehensive assessment of acid reflux. The test can identify the frequency and duration of acid reflux episodes, as well as the relationship between symptoms and reflux events. This information is essential for diagnosing GERD and evaluating the effectiveness of treatment.
**Why Each Wrong Option is Incorrect**
**Option A:** Endoscopy is a valuable diagnostic tool for GERD, but it primarily evaluates the mucosal damage and complications associated with chronic acid reflux. While endoscopy can identify oesophagitis, stricture, and Barrett's oesophagus, it does not directly measure acid reflux.
**Option B:** Barium swallow is a radiographic study that can demonstrate oesophageal motility disorders and structural abnormalities, but it is not a sensitive test for detecting acid reflux.
**Option C:** pH monitoring during a 24-hour period is more accurate than a single pH measurement, which may not capture the full extent of acid reflux.
**Clinical Pearl / High-Yield Fact**
A high intra-abdominal pressure, such as in obesity, pregnancy, or during heavy lifting, can exacerbate gastro-oesophageal reflux.
**Correct Answer:** C. pH monitoring during a 24-hour period.