Forget detoxing - these days it's all about cleansing. After a particularly toxic summer and a tip-off from a friend, I shelled out £24.95 on Renew Life's Cleanse Smart, a 30-day "herbal internal cleanse" that claims to "support the body's seven channels of elimination" (lungs, liver, kidneys, colon, skin, lymphatic system and blood). The programme consists of two tablets morning and evening, a recommendation that you also take Fiber Smart - a dry powder with the consistency of ground-up Weetabix costing £19.95 - and a list of foods to avoid (meat, wheat, dairy, alcohol, caffeine). It also suggests you eat plenty of fruit, vegetables and whole foods.

The idea is that the herbs (such as dandelion, artichoke, milk thistle) and added fibre stimulate the body, helping it to get rid of unwanted waste. "Whole-body cleansing is not just a colon purging. It uses herbs that have traditionally been used to address the support of liver, blood, lymph, lungs, kidney and colon," says Brenda Watson, founder of Renew Life. But doesn't the human body cleanse perfectly well on its own? Rachel Cook of the British Dietetic Association thinks so. "There's no scientific evidence to suggest that our bodies need help to get rid of waste products," she says.

Whatever the outcome, I needed a break from my unhealthy lifestyle and thought this might motivate me to stay on the wagon. On day four, odd things started to happen every time I went to the bathroom. I soon became so obsessed with my bowel movements that I started emailing updates to friends.

I went away twice that month. and fell spectacularly off the wagon both times. I suffered far worse than normal, proving only that it is staggering how quickly the body gets used to clean living. Did I feel any better after the 30 days? Well, yes, but who wouldn't after a month of salads and brown rice?