The recent ruling of the Advertising Standards Authority means that we are not allowed to talk about the effects of Acupuncture and IBS or any other Western Medical conditions without a recognised Western medical study, including control groups using placebos, to back it up.
However, the British Acupuncture Council has produced some useful fact sheets on this subject.
http://acupuncture.org.uk/research-fact-sheets/1135-acupuncture-and-ibs.html
http://acupuncture.org.uk/research-fact-sheets/1134-acupuncture-and-gi-tract-disorders.html
http://acupuncture.org.uk/research-fact-sheets/1302-acupuncture-nausea-and-vomiting.html