The advertisement by ASG, a clinic located at Paragon shopping mall, appeared in The Straits Times on ail 12, 18 and 25.

In the advertisement ASG, said its chief surgeon Dr Peter Goh Min Yih, would be able to provide answers and give evaluations to potential patients.

Both the Society of Colorectal Surgeons (Singapore) and the Asean Society of Colorectal Surgeons said claims of the transanal haemorrhoidal deartcrialisation (THD) being "painless", with "no downtime" and providing "immediate result", were factually wrong.

THD, a precise ultrasound-guided ligation, or tying off, of the blood vessels supplying the piles, is usually performed as day surgery.

It is not a new technique used in treating piles which ars swellings of spongy, blood-filled patches in the wall of the anal canal.

THD has been in use in many countries, including several medical centres here, since 2006.

One in three people in Singapore suffers from piles and the Singapore General Hospital (SGH) has performed about 300 THD procedures.

The societies said while THD is effective in reducing bleeding from piles and less painful than other techniques of piles removal. it is not painless.

"International studies have reported 56 per cent of patients experienced some degree of pain or discomfort on the first day after the operation and required oral pain medication, (and the pain) would gradually reduce over the next two days," they said in a joint letter.

It was signed by Associate Professor Tang Choong Leong and Professor Eu Kong Weng, the presidents of the two societies and Dr Francis Seow-Choen, the past president of the Society of Colorectal Surgeons (Singapore).

When contacted, Dr Goh dismissed the surgeons' comments as making "a big issue out of a molehill".

"Pain is a relative thing ... from our experience, our patients have described the procedure as pain-free and they do not take many medications for it. They even go back to work the next day," he said.

"If you want to be absolute about it, then yes, it's not 100 per cent pain-free, but if you look at it in depth there is so little pain that it can be considered pain-free."

His clinic has done 10 of these procedures since it started offering THD about two weeks ago.

Dr Seow-Choen, a colorectal surgeon in private practice, said that THD is a treatment used only for "recalcitrant bleeding second- and third-degree piles and not for all piles".

"It is just a more thorough ligation method and no piles are removed. Some patients do have substantial pain although many have only an aching heavy feeling for a week or so. It works well in selected cases but it is not for those with prolapsed piles," he said.

Prof Eu, who heads SGH's department of colorectal surgery, said out of the 300 patients who had TIHD procedures done in his department since September last year, two resulted in bleeding and had to be hospitalised.

"The rest were given two to three days' medical leave to stay home after the operation so it is not true there is no downtime," he said.

Prof Eu added that a study by his department found 3 per cent of patients had mild residual discomfort even after two weeks. The results of the study are being analysed for publication.

Dr Goh said that his group will remove the term "painless" from future ads and will include the different modalities of treatment of piles.

He said the ads were to invite patients to attend educational talks on piles and the group has been highlighting the different treatment methods available, spending only five minutes on the THD method.

"We just started offering the procedure and acknowledge that they are the pioneers," he said.