A Bravo procedure is a test that measures acid levels in your esophagus over 48 to 96 hours using a tiny wireless capsule. It’s the primary tool doctors use to confirm whether you have gastroesophageal reflux disease (GERD), especially when symptoms are unclear or don’t respond to treatment as expected. Unlike older methods that required a tube threaded through your nose, the Bravo system uses a small capsule temporarily attached to the wall of your esophagus, letting you go about your normal routine while it collects data.
How the Capsule Works
The Bravo capsule is about the size of your smallest fingernail, measuring roughly 6 mm by 5.5 mm by 25 mm. It has a pH sensor at one end that detects acid levels, taking two readings every six seconds and transmitting that data wirelessly to a small recorder you wear on a belt around your waist. The recorder is about the size of a computer mouse. During sleep or bathing, you need to keep the recorder within 3 to 5 feet of your body for the signal to come through.
The capsule’s battery can last up to 14 days, though most studies only need 48 to 96 hours of data. After the monitoring period ends, the capsule detaches from your esophageal wall on its own, typically within 7 to 10 days. It passes through your digestive system naturally and is eliminated without you needing to retrieve it.
Why It Replaced the Nose Catheter
Before wireless monitoring, the standard test involved threading a thin catheter through your nose and down into your esophagus, where it stayed for 24 hours. Patients frequently reported nasal and throat discomfort that led them to eat less and avoid their usual activities. The visible tube also made people self-conscious, which meant they changed their behavior during the test. That’s a problem: if you’re not eating, drinking, and moving the way you normally do, the test may undercount how much reflux you actually experience.
Studies comparing the two methods found that the wireless system significantly reduced disruptions to daily life. Patients using the catheter reported roughly three times more limitation of daily activities and more than twice the impact on food intake compared to those using the Bravo capsule. The wireless approach also extends the monitoring window beyond 24 hours, which gives a more complete picture of your acid exposure patterns across different days.
What Happens During Placement
The capsule is placed during an upper endoscopy, a brief procedure where a thin, flexible tube with a camera is guided down your throat to view your upper digestive tract. You’ll receive sedation beforehand, and most patients sleep through the entire process. Once the doctor identifies the right spot in your lower esophagus, the capsule is attached to the esophageal lining using a small suction-based delivery system. The whole procedure is typically quick, and you go home the same day.
How to Prepare
Accurate results depend on stopping certain medications well before the test, since these drugs change your acid levels and would skew the readings. The timeline works in three stages:
- 7 to 10 days before: Stop proton pump inhibitors (common brands include Prilosec, Nexium, Prevacid, and Protonix).
- 3 days before: Stop acid reducers like Pepcid and similar medications.
- The night before: Stop over-the-counter antacids like Tums, Maalox, and Gaviscon.
Your doctor’s office will give you specific instructions, but the general principle is the same: any medication that suppresses or neutralizes stomach acid needs to be out of your system so the test captures your true baseline.
What You Do During the 48 to 96 Hours
Once the capsule is in place and you’re home, the goal is to live as normally as possible. Eat your usual meals, lie down when you normally would, and go through your typical routine. That’s the whole point of wireless monitoring: your results reflect real life, not a day spent avoiding food because a tube is bothering your throat.
You’ll be asked to press buttons on the recorder whenever you eat, lie down, or experience symptoms like heartburn or chest discomfort. You’ll also keep a written diary noting the times of these events. This log is essential because it lets doctors correlate your symptoms with the actual acid levels the capsule records. If your esophagus shows a spike in acid at the exact moment you felt burning in your chest, that’s strong evidence connecting your symptoms to reflux.
What the Results Mean
After the monitoring period, you return the recorder. Your doctor downloads the data and analyzes two key metrics. The first is acid exposure time, which measures what percentage of the monitoring period your esophagus had a pH below 4 (meaning it was acidic). Anything above 4% of total time is considered abnormal. The second is a composite score called the DeMeester score, which combines several measurements into a single number. A score above 14.7 indicates abnormal acid reflux.
These numbers help your doctor confirm or rule out GERD, determine its severity, and decide whether you’re a candidate for treatments like anti-reflux surgery. They’re particularly useful for people whose endoscopy looks normal but who still have persistent symptoms, a condition called non-erosive reflux disease.
Side Effects and Risks
Most people tolerate the Bravo capsule well. The most common sensation is a mild feeling of something in your chest, similar to a pill that hasn’t gone all the way down. Some people notice discomfort when swallowing for the first day or two.
In rare cases, the capsule can irritate the esophageal lining enough to cause significant chest pain. This pain can feel alarming because it sometimes mimics the symptoms of a heart problem. If the discomfort becomes severe, doctors can perform an endoscopy to remove the capsule early.
One important safety note: MRIs are not safe for 30 days after capsule placement. Even though the capsule usually detaches and passes within 7 to 10 days, the 30-day window accounts for the small chance it’s still somewhere in your digestive tract. If you need an MRI for any reason during that period, let your medical team know you’ve had a Bravo procedure.