TREATMENT OF IRRITABLE BOWEL SYNDROME WITH CHINESE HERBS
Irritable bowel syndrome is one of the most common intestinal complaints presented to medical doctors (1). Direct intestinal examinations (e.g., endoscopy) usually show no obvious abnormality inside the intestine. Other tests show no significant changes in absorption of nutrients or nutritional status. A characteristic of the disorder is spasm of the intestinal muscles, which produces discomfort, including pain, bloated feeling, and urgency; defecation usually provides temporary relief of the symptoms. The disorder has been called spastic colon, as a reflection of the apparent underlying problem. Frequent bowel movements, sometimes described as a case of diarrhea, occur during certain phases of the disorder; at other times, there is constipation. The constipation may be the combined result of several factors, such as a low fiber diet, inadequate fluid intake, and the after-effect of having several bowel movements on one or more previous days; in addition, if the intestinal musculature is in a tonic condition (a continuing contraction without the pulsation of spasms or normal peristalsis), that will tend to cause constipation.
It is generally believed that nervousness contributes to irritable bowel syndrome. The disorder is sometimes called intestinal neurosis to reflect this. Bowel problems are amplified during times of emotional distress. However, the irritability of the nerves affecting the intestinal muscles may be brought on by other factors as yet undetermined. Although dietary constituents have been suggested to be a problem, the results of investigations have been mixed. Certainly, food allergens may trigger bouts of spasm and diarrhea. A high fat meal induces discharge of bile from the gallbladder, which stimulates intestinal peristalsis: in persons who tend to get intestinal spasms, this might be enough to trigger the response.
A condition corresponding to irritable bowel syndrome was described in early Chinese literature, with a specific formula recommended: Bai Zhu Shao Yao San (Atractylodes and Peony Powder), later named Tong Xie Yao Fang (Formula for Painful Diarrhea). According to Formulas and Strategies (2), the first mention of the formula was in a 15th Century text, but the official recognition of it comes from Jing Yue Quan Shu, published in 1624; the indications for the formula are "recurrent problems of borborygmos, abdominal pain, diarrhea with pain (which starts with the urge to defecate and subsides after completion)."
The simple four herb formula-peony, atractylodes, citrus, siler-has been classified as one of the important harmonizing prescriptions (see Exploring Yin/Yang #7), having the property of regulating the functions of the liver and spleen. It is related to the famous harmonizing prescription from the Shang Han Lun: Bupleurum and Chih-shih Formula (Si Ni San), which also has four herbs-peony, licorice, chih-shih, and bupleurum.
In this newer formula, bupleurum is replaced by siler, chih-shih is replaced by citrus, and licorice is replaced by atractylodes. In Tong Xie Yao Fang, siler is utilized to spread the liver qi in the same manner that bupleurum does; it also causes the qi to rise (as does bupleurum), but it differs from bupleurum in that it is more supportive of the spleen functions. Chih-shih also spreads liver qi, but it tends to help the downward draining of accumulation. Chih-shih is often used to treat constipation, as in the Minor and Major Rhubarb Combinations (Xiao Zheng Qi Tang and Da Zheng Qi Tang) and it is used to treat abdominal pain in combination with peony (as in the formula Zhishi Shaoyao San, made of just those two herbs). However, when the main focus of the treatment is diarrhea, chih-shih (which is an immature citrus fruit) is usually replaced by citrus; chih-ko or fu-shou would also do and are sometimes substituted or added in modern versions of Tong Xie Yao Fang. Licorice is replaced by atractylodes in this formula because atractylodes is better at calming diarrhea; both serve as qi tonics that benefit the spleen. Still, with all the replacements, the basic functions of these two formulas remain the same: to enhance the spleen function and spread the liver qi. Both formulas are indicated for abdominal pain and diarrhea; Tong Xie Yao Fang focuses on problems of painful diarrhea, while Si Ni San focuses on other problems of liver disharmony, such as cold limbs.
In the majority of modern clinical applications for irritable bowel syndrome, Tong Xie Yao Fang, applied as a basic harmonizing formula, is often the prescription of choice, to be modified according to the herbalist's own perception of what works best for this disorder, and also according to what is needed for specific cases. However, some physicians pursue a course of fuller differential diagnosis and use alternative prescriptions for the minority of cases that are not deemed to be due to the liver/spleen disharmony.
The Chinese literature does not contain many references to irritable bowel syndrome. However, there are a few reports that include this syndrome; three examples are described here.
In 1985, Li Yujun and Zhou Xitin reported (3) on treatment of 45 cases of patients suffering from recurrent diarrhea. The patients were subdivided into four groups according to differential presentation, with two groups representing an irritable bowel syndrome (based on symptoms, such as abdominal pain alleviated with bowel movement). One group was treated with herbs to harmonize liver and spleen, using the following combination derived from Tong Xie Yao Fang: peony, atractylodes, siler, citrus, saussurea, polyporus, hoelen, chih-ko, rose fruit, and licorice. In this case, polyporus and hoelen are added to remove dampness and rose fruit to astringe the intestines to treat diarrhea. The other group was treated with herbs to harmonize cold and heat. The combination, derived from Mume Formula (Wumei Wan), was: asarum, zanthoxylum, aconite, roasted ginger, coptis, phellodendron, codonopsis, atractylodes, hoelen, licorice, and mume. Here, coptis and phellodendron-bitter fire-purging herbs-stand in stark contrast to aconite, zanthoxylum, asarum, and aconite-strongly spicy and heating herbs. Codonopsis, atractylodes, hoelen, and licorice comprise the Four Major Herbs Combination (Si Junzi Tang), strengthening the spleen. Mume serves as an intestinal astringent. The traditional Wumei Wan is usually described as a treatment for intestinal parasites, though only two of its ingredients are recognized antiparasitic herbs: zanthoxylum and mume. The traditional formula has been adopted for use in treating indigestion, gastritis, intestinal spasms, chronic diarrhea, and other gastro-intestinal disorders.
The rate of effectiveness of the formulas for patients with irritable bowel syndrome could not be extracted from the generalized data on treatment of all the groups that suffered from some type of diarrhea, but the approach to treatment is clear from the formula selections. The mean course of treatment was one month.
In another study published in 1985, Zheng Xian also reported (4) on differential treatment of several types of intestinal dysfunction, including a group corresponding to irritable bowel syndrome. Those individuals were treated with the following derivative of Tong Xie Yao Fang: peony, atractylodes, siler, citrus, fu-shou, chih-ko, magnolia bark, hoelen, pogostemon, cyperus, saussurea, codonopsis, and licorice. In this case, additional herbs for regulating qi and moisture were added to the base formula. In particular, three types of citrus (chenpi, fushou, and zhiqiao) were included; these benefit the spleen, disperse stagnant qi, and calm the intestinal muscles. As with the previous study, results for the irritable bowel subgroup could not be extracted from the general data; the treatment time for this subgroup was given as 15 days.
In 1988, Guo Zongmeng reported (5) on treatment of "gastrointestinal dysfunction," in a large number of patients: Air Force pilots, who, he reported, have a high tendency to get this disorder. The basic condition described appears to be irritable bowel syndrome. Several different treatments were offered, including decoctions of Tong Xie Yao Fang and other traditional formulas indicated for diarrhea; some patent medicines (mainly Fuzi Lizhong Wan and Renshen Jianpi Wan), and the author's own formula for this disorder, made as an extract and then formed into pills. The latter contained: red peony, atractylodes (half white, half red), citrus, siler, codonopsis, ginger, cinnamon bark, hoelen, psoralea, galanga, piper, nutmeg, coptis, and evodia. This formula is based on Tong Xie Yao Fang, but red peony replaces white peony, white atractylodes is joined by red atractylodes, and there is a group of warm spicy herbs added (cinnamon bark, ginger, psoralea, galanga, piper, nutmeg, and evodia) with only a very small amount of bitter-cold coptis. Some patients received two of the above types of treatment together (e.g., decoction plus pills). Overall, the treatment time was an average of 20 days and the "markedly effective group," those who responded best to the treatment, comprised about 40% of the patients (only 11% were described in terms of ineffective treatment, the rest showed some degree of improvement).
One of the few studies found in the literature that was aimed specifically at irritable bowel syndrome was a 1990 report by Huang Suiping (6). He used a modified Tong Xie Yao Fang, which he called Tiao Gan Fang. It is comprised of peony, atractylodes, chih-ko, siler, saussurea, and a rarely-used species of ilex (Ilex rotunda; jiubiying, it is bitter and cold, clears heat and toxins, promotes diuresis and eliminates wetness, and alleviates pain). The formula could be modified for cases of notable spleen deficiency by adding astragalus and codonopsis, or for cases of dampness, by adding coptis. The study was relatively small (30 patients), making it somewhat difficult to evaluate the results. It was a placebo-controlled cross-over study, with half the patients receiving the pilled Tiao Gan Fang or a matched placebo pill; then, after a two week period, reversing the treatments. Treatment time was 21 days. Unfortunately, full data for the two treatment periods were not detailed, but, the overall data suggested that about 72% of those showing IBS symptoms at the start had the symptoms alleviated after three weeks of the herb formula, while only 14% of those in the placebo group had the same result.
These published studies indicate that Tong Xie Yao Fang remains the basis for traditional herbal treatment of irritable bowel syndrome, though modifications are made and other formulas are also used at times. The typical treatment time, in these clinical trials, was 15-30 days.
Constipation associated with irritable bowel syndrome is to be treated by consuming more fiber in the diet and consuming more water. It has been reported in European medical journals that peppermint oil can help treat irritable bowel syndrome via an antispasmodic action on the intestinal nerves (enteric coated soft gelatin capsules are sometimes used for this purpose). This same action is likely to occur from the essential oil ingredients of herbs such as atractylodes, pogostemon, nutmeg, saussurea, cyperus, and other aromatic herbs used in the Chinese treatment of irritable bowel syndrome.