Black Sabbath rocker Ozzy Osbourne's son Jack is pleased he endured the hardships of colonic irrigation twice daily, because his significant weight loss leaves him speechless.

The formerly overweight Jack lost a staggering 4.5 kilograms (10 pounds) every day in the radical week-long detox in Thailand, which also served to cure his alcohol and drug addictions.

But Jack, 19, feels the discomfort was worthwhile as he was amazed at the change in his appearance.

He says, "That was one of the most miserable weeks of my life.

"It was hot sticky and boring. I had a tube up my a** twice a day and five litres of coffee poured in. It wasn't painful but the pressure was uncomfortable.

"I was camping in a little hut in Thailand, so I went for weeks without seeing my reflection.

"And when I finally looked in the mirror four weeks later I spent ages looking at myself thinking, 'Wow.'"