A ''smart toilet'' that recognises users by the shape of their bottoms has been developed in the US.

Bizarre on Female First

Bizarre on Female First

Researchers at Stanford University have added cameras and motion sensors to the toilet to analyse urine and faeces as they pass through, with the aim of identifying a range of disease markers in faecal matter.

The process involves an ordinary toilet being fitted with the gadgets to perform the tests and has a companion app to analyse the data and display the results.

The researchers who developed it hope it becomes part of the average home bathroom.

Sanjiv Gambhir, the professor behind the idea, said: ''We know it sounds weird, but as it turns out, your anal print is unique. Our concept dates back well over 15 years.

''When I'd bring it up, people would sort of laugh because it seemed like an interesting idea, but also a bit odd.

''The thing about a smart toilet is that, unlike wearables, you can't take it off. Everyone uses the bathroom - there's really no avoiding it - and that enhances its value as a disease-detecting device.''