In a move reminiscent to the 1966 science fiction movie in which a miniature submarine enters a human body, Royal Preston Hospital has unveiled its own mini-camera 'submarines'.

By swallowing video capsules the size of a pill, patients will allow doctors to record the journey of the camera through the small intestine to help diagnose gastrointestinal and digestive diseases.

Around 50,000 colour images are captured by the camera during the pill's eight-hour life span and these are transmitted through a special body belt.

The amazing technology can lead to a rapid diagnosis and can change the treatment of patients and even save lives.

It has detected ulcers in the small intestine and in one case, it detected multiple bleeding points from abnormal vessels within the small bowel, some of which were seen to be actively bleeding during the procedure.

Dr Philip Shields, consultant gastroenterologist at Lancashire Teaching Hospitals NHS Foundation Trust, who set up the service, said: "Visualising the small intestine has previously been very difficult as it cannot be reached by a standard flexible viewing telescope or endoscope.

"Patients undergo standard bowel preparation and then swallow a large pill which features a special miniature camera and flash which takes two colour pictures every second and transmits its pictures via a special body belt.

"The whole journey can be downloaded to a computer and viewed as video footage, or as individual images. The pill is passed naturally and fortunately doesn't have to be recovered after the procedure!"