Swallowing a sponge on a piece of string, experts hope, could help prevent a deadly form of cancer.
Medical Research Council scientists have created the "cytosponge" which collects cells from the stomach, reports the BBC.
These cells can be checked for a pre-cancerous condition called Barrett's oesophagus, which can affect people with a long history of heartburn.
One in 10 people with the condition will go on to develop oesophageal, or food pipe cancer.
The team says the cytosponge could be used in primary care as an inexpensive and easily administered test.
When the sponge is swallowed, it expands to a three-centimetre mesh in the stomach. It is pulled out after five minutes and the cells it collects can then be analysed in the lab.
The researchers, from the MRC's Cancer Cell Unit in Cambridge, tested the device on 500 patients aged between 50 and 70, who also had endoscopies to check the results.
The sponge detected over 90 pc of cases of Barrett's oesophagus.
The MRC's study is reported in the British Medical Journal.