In Reply: Dr Lu provides an interesting perspective
on the potential pharmacological basis of action of CHM. It could also be
postulated that there is a direct pharmacological action affecting visceral
hypersensitivity—1 of the central mechanisms that appears to be dysregulated
in IBS. While it is likely that there is a synergism between certain herbs,
it is also possible that not all the herbs are efficacious.
The standard formula was devised through the study and collaboration
of 2 principal Chinese herbalists. While contained within it are parts of
classic formulations, it does not strictly follow previous prescriptions.
The placebo was prepared by a pharmaceutical contractor with previous experience
in this area. It contained 78.2% calcium hydrogen phosphate, 19.6% soy fiber,
0.3% cosmetic brown, 0.5% cosmetic yellow, 0.01% edicol blue, 0.09% identical
licorice dry flavor, and 0.3% bitter flavor. We are reasonably confident that
the placebo was completely inert. Patients who received the placebo responded
in a predictable fashion overall. The gram proportions of herbal ingredients
in the standard formula were converted to the nearest 0.5%.