Citation: Wikipedia

Irritable bowel syndrome (IBS or spastic colon) is a diagnosis of exclusion. It is a functional bowel disorder characterized by chronic abdominal pain, discomfort, bloating, and alteration of bowel habits in the absence of any detectable organic cause.[1] In some cases, the symptoms are relieved by bowel movements.[2] Diarrhea or constipation may predominate, or they may alternate (classified as IBS-D, IBS-C or IBS-A, respectively). IBS may begin after an infection (post-infectious, IBS-PI), a stressful life event, or onset of maturity without any other medical indicators.
Although there is no cure for IBS, there are treatments that attempt to relieve symptoms, including dietary adjustments, medication and psychological interventions. Patient education and a good doctor-patient relationship are also important.[2]
Several conditions may present as IBS including celiac disease, Fructose malabsorption,[3] mild infections, parasitic infections like giardiasis,[4] several inflammatory bowel diseases, functional chronic constipation, and chronic functional abdominal pain. In IBS, routine clinical tests yield no abnormalities, though the bowels may be more sensitive to certain stimuli, such as balloon insufflation testing. The exact cause of IBS is unknown. The most common theory is that IBS is a disorder of the interaction between the brain and the gastrointestinal tract, although there may also be abnormalities in the gut flora or the immune system.[5][6]
IBS does not lead to more serious conditions in most patients.[7][8][9][10][11] But it is a source of chronic pain, fatigue, and other symptoms, and it increases a patient’s medical costs,[12][13] and contributes to work absenteeism.[14][15] Researchers have reported that the high prevalence of IBS,[16][17][18] in conjunction with increased costs produces a disease with a high societal cost.[19] It is also regarded as a chronic illness and can dramatically affect the quality of a sufferer’s life.

DO YOU regularly feel abdominally bloated?
DO YOU suffer abdominal pain which can be dull or sharp in nature?
DO YOU possibly suffer regular symptoms of any of the following?

Excessive wind, indigestion, acid reflux, rectal mucus, constipation or diarrhoea, or do you alternate between both? DO YOU also feel the need to open your bowel but nothing happens? Conversely, DO YOU feel you have finished, but the urge to open your bowel returns again, yet nothing happens?

If you have experienced recurrent abdominal pain, or abdominal discomfort with a marked change in bowel habits for at least six months, with symptoms experienced on at least 3 days per month during the previous 3 months, and the abdominal pain or discomfort is associated with two or more of the following: Pain is relieved after opening your bowel; the onset of pain is associated with a change in the frequency of stool and/or the onset is associated with a change in the form or appearance of the stool, (1,2) then you might be suffering from irritable bowel syndrome.

If you wish to finally do something positive that will not only impact on your pain and discomfort, but most importantly, improve your quality of life, then call York City Health Clinic today and make an appointment to see Mr John D. McGuire. Finally, you can become proactive in the treatment of your disorder and work in partnership with a practitioner who did his Master’s Dissertation (with distinction) at university on irritable bowel syndrome!

1. Hotoleanu C, Popp R, Trifa AP, Nedelcu L, Dumitrascu DL. Genetic determination of
irritable bowel syndrome. World J Gastroenterol 2008; 14(43): 6636-6640

2. Barbara Bradley Bolen, Ph.D. About.com Guide May 16, 2008
ibs.about.com/od/glossary/g/Rome.htm

Dietary modifications, fibre, probiotics and herbal medicine for the common complaint are reviewed by John D McGuire and Philip A Towers.

John D McGuire DBM, ND, D.H.T., DH Pharm (Post Grad), BHlthSc (comp med), MHlthSc (comp med), MATMS, MCMPAC, MNHAA, is a practicing naturopath, health scientist and researcher at Charles Sturt University; Director of York City Health & SEARCH Scientific & Education.

Philip A Towers, BSc (Hons), MappSc., PhD, is a Senior Lecturer in Physiology at Charles Sturt University

Irritable bowel syndrome (IBS) is a common, debilitating, multifactorial, functional gastrointestinal disorder where a definitive aetiology has not been established and no uniformly successful treatment exists. The condition is very prevalent in developed countries with IBS symptoms experienced by 8-22% of the population¹. IBS thus poses a significant economic burden on the community as well as the individual.

IBS is characterised by a combination of symptoms and signs, such as abdominal pain, constipation (IBS-C), diarrhoea (IBS-D) — or alternating between both (IBS-A) — a noted change in both the frequency and consistency of stools, rectal mucus due to hypersecretion of colonic mucus, dyspeptic symptoms including anorexia, flatulence, gastro-oesophageal reflux (GOR) and nausea, and an emotional component where anxiety and/or depression are often noted. Abdominal pain is often relieved following defecation.

Although some genetic predisposition may exist for IBS, no biological marker exists and diagnosis is now usually based on symptoms meeting the Rome II criteria. Originally, diagnosis for IBS was made based on the Rome I Criteria. This previous criteria specified that there should be at least 3 months of abdominal pain, either continuous or recurrent, that is relieved by defecation &/or is associated with either a change in the frequency  or consistency of the stool. Conversely, the Rome II Criteria differs from that of the Rome I in that it specifies that the abdominal pain should be present either continuously, or recurring for a period of 12 weeks or >. Both the Rome I & Rome II Criteria are consistent in their description of what constitutes accompanying symptoms, i.e., relief of abdominal pain following defecation, &/or associated changes in both the frequency & consistency of the stool, but the Rome II Criteria is more specific in stipulating that at least 2 of these accompanying symptoms must be noted, along with abdominal pain. Although the Rome I Criteria was also quite detailed in specifying that an individual had to have 2 or more associated symptoms of IBS, e.g., altered stool frequency of more than 3 per day or < 3 per week; abdominal distension; bloating; passage of mucus, etc, > 25% of the time, the newer Rome II Criteria has helped in simplifying the diagnosis of IBS. Where patients are <45 years of age, & they meet three or more of the Rome II diagnostic criteria (without ominous symptoms), a confident diagnosis can be provided without the need for invasive testing.

It has also been suggested that IBS is a psychosomatic illness; although the evidence for this appears to be equivocal, IBS patients have been found to have significantly higher scores on the Beck Depression Inventory (BDI) and the State-Trait Anxiety Inventory (STAI). From a study conducted at the Centre for Stress and Anxiety Disorders (the University at Albany), IBS patients successfully treated with cognitive and behavioural procedures showed significant reductions in both BDI and STAI scores².

Pathophysiology

IBS can develop from a number of different mechanisms. Several have been proposed, including abnormal colonic fermentation or gallbladder motility; altered microbial flora; anxiety/depression; bacterial gastroenteritis; an exaggerated sensory component of the gastrocolonic response; food allergy, intolerance or sensitivity; gastro-oesophageal reflux; impaired transit time or tolerance of intestinal-gas loads; increased gut sensitivity; low-grade mucosal inflammation; motility disorder; myenteric plexus neuronal degeneration; oxytocin-increased thresholds for visceral perception; rectal hypersensitivity; and visceral hypersensitivity.

Irrespective of the mechanism by which IBS develops, symptoms typically relate to altered gut motility, resulting in abnormal transit of gas and stool.

Conventional treatment

Conventional drug therapy involves the prescribing of antispasmodics/anticholinergics (used in the treatment of gastrointestinal spasm), antidiarrhoeals, laxatives, serotonin receptor agonists (for IBS-C), serotonin-receptor antagonists (for IBS-D) and SSRIs for associated anxiety, depression, obsessive-compulsive behavior and panic disorders. These drugs typically have wide-ranging side-effects; however, their actions and adverse reactions are beyond the scope of this review. There does not appear to be any universal agreement in the management of IBS. With regards to a conventional approach and patient education, if advice is offered, most are only advised to increase their dietary fiber intake (e.g., wheat bran) or in addition, supplement with say, ispaghula or psyllium husks. Some practitioners do however recognize the importance of stress management & counseling.  

Diet

Most dietary studies relating to IBS have been observational, and only small proportions are randomised controlled trials. Nevertheless, they are useful in suggesting treatment options.

Gas, diet and IBS

The daily production of gas in the human gastro-intestinal tract (GIT) is 500-1500ml, and the volume found at any given time is 200ml.  Five major gases are responsible for the development of flatus, i.e. carbon dioxide, hydrogen, hydrogen sulphide, methane, and oxygen. Oxygen found in the GIT is the result of swallowed air during the course of eating and drinking (aerophagia), or it may be due to hyperventilation in cases of anxiety. Greater amounts would be expected in subjects who eat too quickly, chew gum, or smoke, as not all is absorbed or expelled following belching.

The human large intestine is host to at least 400 different bacterial species, and examples include carbohydrate-fermenting bacteria, methane-generating bacteria (methanogens), and pectinolytic bacteria. These bacteria are responsible for the production of carbon dioxide (the main gaseous product), hydrogen, hydrogen sulphide, and methane. Flatus is the by product of fermentable substrates (carbohydrates and proteins). Examples of these fermentable substrates include: beans, cabbage, Brussel sprouts, broccoli, and whole grains (which contain raffinose; and fruit, onions and wheat (which contain fructose). These nonabsorbable carbohydrates, together with ingested sugars such as fructose found in fruits, dietary starches (that escapes small intestinal absorption), e.g. potatoes, corn, wheat; and dietary fibre, such as that found in oat bran, beans, and peas, are all capable of producing gas. This is the result of these foods being metabolised by the colonic flora, followed by bacterial fermentation.

A number of different treatment options are cited within the literature for IBS; however, dietary modifications are not viewed as a priority in many cases. Sulphur-containing foods such as beans, broccoli, Brussels sprouts, cabbage, cauliflower, garlic and onions have been identified as being extremely flatulogenic.³ Evidence relating to the exclusion of sulphur-containing foods is limited and, in many cases, dismisses exclusion diets as being of no use, limited use, or not proven to be effective.^4,5 Nevertheless, other studies acknowledge that some foods may play a role in producing gas in the IBS patient.^3,6-12

The sulphur-containing amino acids cysteine, cystine, methionine and taurine are the main sources of dietary sulphur. Other sources are derived from glucosinolates found in Brassica vegetables (broccoli, Brussels sprouts, cabbage, cauliflower and turnip).¹³ In garlic and onions, the organic sulphur compounds are found in the form of diallyl thiosulfinates (allicin). Other dietary sources of sulphur are derived from meat or food additives used as preservatives (e.g. sulphur dioxide and sodium metabisulphite). Magee et al¹³ found a significant dose-related increase in faecal sulphide concentrations associated with the intake of meat.

Some oligosaccharides, such as raffinose and stacchiose, appear to be the most important sources of gas from bean digestion, as these compounds cannot be degraded by intestinal mucosal enzymes.^3,14 It might be expected that, following fermentation, these complex carbohydrates contribute to abdominal distension and bloating in IBS patients. Again, these patients might only demonstrate a greater sensitivity to due to their reduced gas handling ability as a result of altered motility. Information within the literature is limited as to the gas-producing ability of sulphur-containing foods and oligosaccharides, and addressing this knowledge gap may be important step in the treatment of IBS.

Food allergy/hypersensitivity

Food allergies and/or sensitivities are an IgE-mediated immunological response to foods that release inflammatory mediators, whereas food intolerance is a non-immunologically mediated adverse reaction. Although the use of IgE RAST or skin-prick testing might prove positive to a number of foods in IBS patients, other researchers have proposed testing for IgG antibodies to exclude food sensitivity. A correlation between raised IgG antibodies and foods known to exhibit a sensitivity response in IBS patients has been demonstrated.¹⁵ This study demonstrated that by eliminating all foods in which a prior sensitivity was detected and demonstrated by raised IgG antibodies resulted in a significant improvement in IBS symptoms. Further studies examining the effects of foods capable of raising serum IgG levels in IBS patients suggest IBS may be related to an immune response^16-18

Food intolerance

Studies have been conducted to determine whether intolerance to specific foods can result in IBS.^3,6-8,10-12 Of 35 different food items, the principal foods reported by participants implicated in development of IBS symptoms included cabbage (57 per cent), onion (56 per cent), peas/beans (46 per cent), hot spices (45 per cent), deep-fried food (44 per cent), coffee (39 per cent) and cream (37 per cent). The major symptoms reported were gas problems, pain, postprandial dyspeptic symptoms, and abdominal discomfort. Furthermore, the results support current opinion that not all IBS patients benefit from an increase in dietary fibre. However, reports discount the impact of foods on aggravating the symptoms in IBS patients.^4,19-20 This reaffirms the discrepancies seen throughout the literature concerning dietary modifications, which understandably leads to confusion as to what foodstuffs should be excluded in treating IBS patients.

Sorbitol and xylitol

Sorbitol and xylitol are artificial sweeteners found commonly in many food items.³ Unlike glucose, intestinal absorption of xylitol is slow^3,21 and in the presence of increased motilin levels, intestinal transit time is decreased. Furthermore, large doses (>30 g) of xylitol can produce diarrhoea in most healthy individuals.²¹ Large doses of sorbitol can induce osmotic diarrhoea, bloating and pain^3,22 and therefore it is possible that smaller doses might aggravate symptoms in IBS patients, particularly those who are diarrhoea predominant.

Fructose

Studies have identified a possible correlation between fructose intolerance and many IBS symptoms, such as altered bowel frequency, bloating, flatus and pain. IBS patients who tested positive following a fructose breath test, and limited their daily fructose intake, had their symptoms improve significantly.^23,24 Abnormal colonic fermentation has been noted in IBS patients⁶ thus it is feasible that fructose malabsorption within the small intestine might lead to an increase in symptoms if fructose is fermented in the large intestine by the action of colonic microflora.⁶

Fat

Increases in the dietary lipid content causes an increase in small-intestine motility, and the gastro–colic reflex response in IBS patients has been noted as prolonged and exaggerated, leading to exacerbation of gastrointestinal symptoms in IBS patients.^9,25 However, dietary lipids inhibit intestinal gas transit, and this mechanism is upregulated in IBS patients.²⁵

Lactose

The symptoms of lactose malabsorption (bloating, osmotic diarrhoea) are similar to those of IBS, suggesting that lactose may be a dietary cause in some individuals. Without the enzyme lactase, lactose cannot be hydrolysed in the small intestine and thus could be fermented in the colon.³ It is also possible that alterations to colonic micro-flora might be involved in the development of IBS in lactose-intolerant individuals. Low-grade inflammation of the colon, and also the effects of post-infective enteritis, might be a cause of lactose intolerance in some IBS patients. Lactase function decreases with inflammation, but generally can regenerate within 1–2 weeks following an episode of enteritis.²⁶

Gluten and gliadin

In one study, 35 per cent of IBS-D-predominant patients with suspected coeliac disease were found to be HLA genotype-DQ2-positive, and 23 per cent had increased intra-epithelial lymphocytes. ²⁷ In this group of patients, symptoms significantly improved after a six-month period on a gluten-free diet. Intestinal IgA levels and stool frequency decreased significantly in those IBS patients who demonstrated a positive response to both markers (HLA-DQ2 and intestinal antibody) compared to IBS patients who tested negative. As oat and rye both contain gliadin, avoidance of these foods, as well as wheat, might benefit IBS-D-predominant patients in whom these markers are shown to be positive.²⁷ To confirm the involvement of such proteins, testing specifically for IgG and IgA to gliadin would seem a logical first step, thus, establishing a clear diagnosis of either coeliac disease or IBS.  

Coffee

IBS symptoms are largely associated with intestinal smooth-muscle activity. Coffee is well known to stimulate gastric and intestinal smooth-muscle activity²⁸ and thus may be a contributing factor in IBS-D individuals. However, decaffeinated coffee may contain approximately one per cent caffeine, and thus IBS-D-predominant patients should avoid both caffeinated and decaffeinated coffee.³

Alcohol

Hydrolysable tannins, as found in red wine, are astringents (causing contraction of mucous membranes and reducing secretion of mucus).²⁹ Thus symptoms experienced by IBS-C and IBS-A patients may be exacerbated by the consumption of tannin-containing beverages, as the tannins may contribute to an increased transit time. Furthermore, tannic acid reduces peristalsis, and high tannin-containing foods may contribute to the constipation seen in both IBS-C- and IBS-A-predominant individuals due to their binding effect.²⁹

Conversely, Dapoigny et al³ state that ‘alcohol is known to induce diarrhoea in abusers through a potential neural mechanism, thereby decreasing transit time’. As IBS-D-predominant patients already demonstrate a decreased transit time, it might again be logical to exclude alcoholic beverages from the diet, despite the sometimes contradictory findings in the literature.

Dietary fibre

The role of dietary fibre in the treatment of IBS is controversial and a broad range of foods containing significant amounts of fibre, including cereals, fruits, vegetables and rice, have been studied⁹. Additionally, studies have been conducted using supplemental forms of both soluble fiber (e.g. partially hydrolysed guar gum, ispaghula, psyllium) and insoluble fiber (e.g. wheat bran).^30-33

A high-fibre diet has been the standard advice provided to IBS sufferers, yet many commercially available preparations (such as those based on the hydrophilic colloids guar gum, psyllium or slippery elm powder) often include herbal laxatives and anthraquinone glycosides, e.g., cascara, Turkey rhubarb and Senna. The end result is that many patients note an increase in their symptoms of pain (colic), abdominal bloating and distension^32,34,35, despite the laxatives present in such products.

In a meta-analysis of randomised controlled IBS trials, 17 studies involved the use of soluble and insoluble fibre. ³² Differences were noted in the outcome of symptom relief, relating to the type of fibre used in each study. In IBS-C-predominant people, soluble-fibre preparations containing calcium polycarbophil and psyllium demonstrated superiority compared to insoluble fibre from corn and wheat bran. However, insoluble fibre in some cases exacerbated symptoms, and the overall benefit of fibre treatments were marginal in improving IBS symptoms. Furthermore, no evidence was found that abdominal pain in IBS could be relieved by the use of fibre. Nevertheless, the overall symptom improvement was statistically significant, and the use of soluble fibre is effective as one facet of treatment for IBS patients.³²

Bran supplementation has also been found to be effective.³¹ In another study, fibre sources other than bran were used; fruit (in particular, citrus fruits) and vegetables demonstrated moderate deterioration of symptoms, with most foods having no effect.³⁵

Psyllium (Plantago spp.) is capable of retaining water due to its hydrophilic nature and, if taken at the correct dose as a supplemental dietary fibre, should both increase the weight of the stool and reduce colon transit time.^30,36 Several studies have confirmed that psyllium can increase stool water content and stool output and is effective in treatment of constipation.^28,32,33 Psyllium also significantly improved constipation in IBS patients, with a decrease in transit time compared to controls.³⁸ Thus, increasing the dose slowly might be of benefit to these patients.^37,38

A multi-site, randomised, double blind, and parallel-design study of 170 subjects with chronic idiopathic constipation was performed³⁹. This study involved a 2-week baseline placebo phase followed by a 2-week treatment phase. The researcher’s intentions were to compare both the stool softening & laxative effect of psyllium with that of docusate sodium (Dioctyl sodium sulphosuccinate). Compared to baseline, they found psyllium to be significantly more effective than docusate sodium for stool water weight per bowel motion (psyllium 84.0g/docusate 71.4g; P = 0.04), stool water content (psyllium 2.33% compared to docusate 0.01%; P = 0.007), total stool output (psyllium 359.9g/week compared to docusate 271.9g week; P = 0.005), frequency of bowel movement (psyllium produced 3.5 bowel movements/week compared to docusate’s 2.9/week; P = 0.02), & stool softening ability. Additionally, the researchers noted psyllium’s stool softening effect increased over the 2-week treatment period. They therefore concluded, that psyllium is a much more efficient laxative compared to docusate due to its stool softening effect, & as a hydrophilic colloid, its ability to retain water makes it a more favorable choice when treating chronic idiopathic constipation.

Probiotics

IBS often develops following gastrointestinal infection and/or antibiotic therapy.Within the literatures, a great deal of attention has been given to the use of probiotics as an adjuvant to treatment, or in the post-treatment of certain gastrointestinal disorders, such as bacterial infections, Crohn’s disease, post-infectious IBS, & following antibiotic therapy.

Barbara et al. (2002) proposed that there might be an increased risk of long-term symptoms of IBS as a result of antibiotics prescribed for the treatment of acute bacterial gastroenteritis. Further, they concluded from prospective studies that between 7% & 32% of individuals who suffer enteritis as a result of Campylobacter, Salmonella, or Shigella demonstrate post-infectious IBS symptoms. In a cohort study, Garcia Rodriguez & Ruigomez⁴⁰ found that patients who suffered gastroenteritis were 10 times more likely to develop IBS in the 12-month post-infection period.  Furthermore, based on animal studies, it has been proposed that probiotics might be of benefit in the treatment of enterocolitis & FGIDs⁴¹.  These studies demonstrated that alterations in intestinal commensal bacterial led to both morphological abnormalities and gut motor dysfunction, and based on experimental evidence, probiotics such as Lactobacillus and Bifidobacterium might play a valuable therapeutic role in the treatment of IBS⁴². Furthermore, L. breve, L. delbruekii, L. casei, L. fermentum, L. longum, L. infantis, L. plantarum, and Streptococcus thermophilus have efficacy in the treatment of IBS⁴³

Botanical medicine

Madisch et al⁴⁴ randomly allocated 208 participants into one of four treatment groups (Table 1), which received either a) a mixture of aqueous–ethanoic extracts containing nine herbs b) a mixture of aqueous–ethanoic extracts containing six herbs c) an aqueous-ethanoic extract of bitter candytuft (Iberis amara) or d) placebo. After two weeks of treatment, a significant decrease in total IBS symptoms was noted in participants who received treatments a or b. A further decrease in IBS symptoms was noted after four weeks, and differences between the treatment group and placebo increased. The improvement noted in both the IBS-symptom and abdominal-pain scales was not limited to any one subgroup, but occurred in all three treatment groups. However, differences observed in the treatment c group failed to reach statistical significance. Nevertheless, two of the herbal mixtures provided results that were statistically significant, and the researchers concluded that these preparations were highly effective in the treatment of IBS.

Table 1

Peppermint oil

Peppermint (Mentha piperita) as an infused tea, tincture, fluid extract or essential oil is probably one the most prominent botanicals used in treating the symptoms of abdominal pain and discomfort in IBS. Traditionally, peppermint has been used as both a gastrointestinal antispasmodic and carminative. Its principal active constituent, menthol, acts as a calcium-channel blocker in intestinal smooth muscle.^45,46 As menthol may relax the gastro-oesophageal sphincter, resulting in oesophageal reflux⁴⁷, the active constituent was delivered to the small intestine in an enteric-coated peppermint-oil capsule (Colpermin; Tillotts Pharma AG, Switzerland) in a subsequent study by Liu et al.⁴⁸  The results are presented in Table 2.

Table 2

Symptom improvement in IBS patients taking Colpermin in this study was statistically significant, as was the case in another study. The severity of symptoms improved in 76 per cent in those taking peppermint oil compared to 19 per cent in the placebo group.⁴⁹ However, these studies were of short duration, with trials lasting only 2–4 weeks; longer periods are required to confirm positive results. When Pittler and Ernst ⁵⁰ conducted a meta-analysis of the efficacy of peppermint oil on IBS treatment, their results were equivocal.

Red peppers

Red pepper (Capsicum spp.) contains the alkaloid capsaicin, which can inhibit release of substance P, which is involved in the function of visceral nociceptive C-type fibres.^29,51 The capsaicin in red peppers may thus reduce the intensity of dyspeptic symptoms. Based on this assumption, a five-week study was conducted to determine the potential of red pepper as a therapy for functional dyspepsia,⁵² with one patient group receiving 2.5 g of red-pepper powder each day (equivalent to 0.7 mg/day of capsaicin) in an encapsulated form.

The results showed a significant reduction in the overall symptoms of epigastric fullness, epigastric pain and nausea. This was proposed to be a result of the constituent capsaicin. Although the exclusion criteria included IBS and gastro-oesophageal reflux disease, this treatment may still have potential specifically for those in the IBS-C subgroup who do not suffer gastro-oesophageal reflux, gastritis or peptic ulcers.

Artichoke leaf extract

One analysis of patients using artichoke leaf extract found 84 per cent reported a significant reduction in the severity of three out of five symptoms of abdominal cramps, abdominal pain, bloating, constipation or flatulence; 96 per cent also found artichoke leaf extract to be comparable to, or even better than, previous treatments.⁵³ Another study reported a significant decline in the occurrence of IBS symptoms (by 26.4 per cent), and changes in alternating defecation patterns (IBS-A) toward normal following artichoke leaf extract treatment. ⁵⁴ The proposed mechanism of action was not discussed and should form the basis of subsequent experimental studies. Traditionally, there are a number of other Western, as well as Chinese, & Ayurvedic herbs used in the treatment of gastro-intestinal problems.

Examples of other Western herbs used in the treatment of IBS include:

Precautions should be taken with long-term (> 2-4 weeks) use of herbs containing anthraquinone glycosides. Furthermore, they are contraindicated in abdominal pain of unknown origin including acute inflammatory intestinal diseases, e.g. Crohn’s disease, ulcerative colitis, etc. 

It is beyond the scope of this review to discuss chemical constituents & pharmacological activities of traditional Chinese medicinal herbs or those used in Ayurvedic medicine, or the four different doshas (termed Grahani: 1.Kapha, 2.Pitta, 3.Vata, & 4.a combination of all three), associated with the Ayurvedic treatment system. or traditional Chinese medicine and its system of prescribing. The efficacy of these additional Western, Chinese & Ayurvedic herbs (with the exception of the study using Chinese herbs in the treatment of IBS conducted by Bensoussan et al ⁵⁵. has yet to be established, as in general, these herbs are not supported by strong scientific controlled studies, and therefore, could in the future form the basis of a wide ranging study in herbal treatments of IBS. However, tables of commonly used herbs used in traditional Chinese medicine and Ayurvedic medicince are included for completeness.

According to Chinese medical theory there are 5 patterns of IBS; chi stagnation and blood stasis, damp heat in the middle burner, deficiency of spleen and kidney yang, spleen and liver disharmony, and spleen yang deficiency.

Placebo effect

With all treatments for IBS, the placebo response must be considered. In some short-term studies, the placebo effect is more pronounced and could average 47 per cent⁸ or even up to 70 per cent³³; thus demonstration of treatment efficacy is difficult. In addition, a higher rate of placebo effect was noted with more frequent interventions.⁵⁵ Jones et al⁸ suggested that ‘higher placebo-response rates may be reflective of greater contact between IBS patients and healthcare professionals’, and ‘the longer the follow up, the smaller the placebo effect becomes’, concluding that the placebo effect could be either maximised or minimised by altering the frequency of dosage.

Conclusion

This article has revealed discrepancies in the use of exclusion diets, differences of opinion in the use of fibre — particularly bulking agents — and the efficacy of herbal medicines in the treatment of IBS. S4 medications carry the risk of adverse reactions and it is hoped that by incorporating a complementary medicine approach, a safer alternative-treatment regime will be employed as one of the first line treatment choices. Alternatively, combining complementary medicine with conventional treatments might reduce the amount of prescribed S4 medication, and thus reduce the possibility of adverse drug reaction.

One theme noted by some researchers³⁵ is that fibre supplements require gradual introduction. Increasing fibre intake too quickly exacerbates the symptoms of abdominal bloating, flatulence and pain in those suffering IBS. The rationale behind the use of bulking agents in IBS or chronic idiopathic constipation is to re-tone the colonic musculature. By doing so, and combined with their stool-softening effect, bulking agents might improve colonic contractile ability, thus assisting in a more complete evacuation of the bowel, leading to a decrease in pain, abdominal bloating and distension as a result of an improved passage of rectal gas. By correcting slow transit time in IBS patients, the symptoms of abdominal bloating, flatulence and pain are greatly reduced or settled. The main goal is to have the patient emptying the bowel well, as this equates to an overall improvement of symptoms. Bulking agents, prescribed in a suitable dose, may also be of value in treating the IBS-D predominant subgroup, as they may help form stools, and thus lessen frequency of bowel movement.

It would be far more beneficial if patients could manage IBS symptoms with bulking agents alone. This would reduce the dependency on laxatives, particularly in IBS-C predominant subgroups. Furthermore, it would be logical to assume that by excluding sulphur-containing foods in the diet, a reduction in fermentation will result, and thus a reduction in colonic gas and subsequent pressure exerted on the upper abdomen and stomach. This is consistent with the suggestion that foods that contain sulphur groups increase the symptoms of bloating, colic and flatulence in IBS. In addition, patients who experience anorexia and/or gastro-oesophageal reflux as part of their IBS symptomatology might benefit by decreasing the level of pressure exerted on the stomach by excluding foods that contain sulphur groups. In all cases, it would seem logical to adjust treatment according to changes in the symptoms shown in the different IBS subgroups; thus it would not be unreasonable to see treatment changed as symptoms resolve.

Summary:

* IBS is a debilitating condition.

* IBS is currently diagnosed using the Rome II criteria.

* Conventional treatment using anti-spasmodics, anti-diarrhoeals, etc, appear to be ineffective.

* Some herbal medicines appear to be effective in the treatment or control of IBS symptoms.

* Further research needs to be undertaken to establish efficacy of a number of complementary medicine (including other herbal medications) treatments for IBS.

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