They are many women's best friend and a staple of the A-listers' wardrobes, Daily Mail reports.

But experts say people who wear these items are compressing their organs. Kim Kardashian once tweeted 'SPANX are my best friend!'.

Gastroenterologist Dr John Kuemmerle, at Virginia Commonwealth University, dermatologist Dr Maryann Mikhail, at Spring Street Dermatology, New York, and chiropractor Dr Karen Erickson, from Erikson Healing Hearts in New York, told The Huffington Post that shapewear can cause acid reflux and heartburn as well as stress incontinence and infections.

Dr Kuemmerle said Spanx compress the stomach, intestine and colon which can lead to acid reflux and heartburn.

Dr Erickson added that they also affect the digestive tract, meaning the intestines struggle to move food through the digestive system.

This, she says, can cause stomach pain, bloating and flatulence.

Dr Kuemmerle says people with irritable bowel syndrome should steer clear of restrictive underwear.

Dr Erickson added that people often avoid going to the bathroom when they are wearing shapewear because it is hard to take off.

This is not the first time doctors have warned of the dangers of wearing Spanx.

It has been claimed that they increase pressure on the lower stomach which forces acid into the gullet which could, over time, increase the risk of ulcers and even oesophageal cancer.

Experts say it is fine to wear control pants on special occasions but that it is not advisable to wear them all of the time. 

The experts claim wearing Spanx can also cause pain and numbness in the legs.

Finally, Dr Mikhail says wearing control pants can cause infections.

This, she says, is particularly common in overweight people and those with diabetes as they tend to sweat more.