Radio 'pill' detects stomach acid to prevent heartburn

Experts at Guy's and St Thomas' are pioneering a treatment using a 26mm-long transmitter to test for it.

The chip can increase the diagnosis rate for heartburn by nearly a third. More than one in three people suffer from chronic heartburn - which is triggered by acid leaking into the gullet and can be as crippling as angina - at least once in their lifetime.

Diagnosis is crucial because surgeons only operate if tests show the body has an unacceptable imbalance of acid.

Until now, doctors have inserted a catheter down the nose and gullet for 24 hours to take an acid reading. One in five patients cannot tolerate this because they gag on the tube or are unable to have it inserted because they have undergone nasal surgery.

The new capsule, which is swallowed, uses radio waves to transmit data on the body's pH levels as it detects when stomach acid enters the oesophagus. The data is recorded on an electronic "diary" which the patient carries.

The pill passes naturally out of the body after use and patients only need to be in hospital for a couple of hours when it is inserted.

Muscle at the top and bottom of the oesophagus stops stomach acid being regurgitated into the throat. But in some people acid leaks through this muscular "trap door", causing chest pain and a burning sensation. Acid reflux can cause a chronic cough which mimics asthma, and increases the risk of cancer.

Terry Wong, a consultant at Guy's and St Thomas, said the probe can stay in the body for up to four days. He added: "This has been revolutionary for diagnosis of acid reflux. If you look at the quality of life with heartburn it's as bad as cardiac failure."

Heartburn sufferer Annette Rose-Warren, 45, had "fast-track" diagnosis at Guy's and St Thomas thanks to the capsule.

Mrs Rose-Warren, from Dulwich, said: "It took them just half an hour to put in the probe. Now I'm feeling better and more comfortable."