What are the symptoms of IBS?
IBS is generally defined as: at least 12 weeks (not necessarily consecutive) in the preceding 12 months of abdominal discomfort or pain that has two out of the following three features:
- Relieved with defecation
- Onset associated with a change in frequency of stool
- Onset associated with a change in form (appearance) of stool.
- Abnormal stool frequency (more than three stools per day, occurring more than three times per week)
- Abnormal stool form (lumpy/hard or loose/watery)
- Abnormal stool passage (straining, urgency or feeling of incomplete evacuation)
- Bloating or feeling of abdominal distension
- Passage of mucus.1
In addition, the following symptoms cumulatively can support the diagnosis of IBS:
Although IBS is characterised by abdominal pain, altered bowel habits and changes in stool frequency, often with feelings of bloatedness and/or distension, other health-related quality-of-life symptoms such as rectal bleeding, heartburn, dyspepsia, flushing, palpitations, migraine and urinary symptoms are also more common in people with IBS.2
According to Jones and Lydeard, “Symptoms consistent with a diagnosis of irritable bowel syndrome (IBS) are present in almost one-quarter of the general population.”3
What causes IBS?
While some experts maintain stress is an important trigger of IBS, others say the psychological factors previously attributed to IBS are actually associated with how well the patient copes with the disorder, rather than the disorder per se.4 Despite this, animal studies have shown that mental stress can impair recovery from inflammatory colitis5 and we know that stress affects the immune system either directly or indirectly through the nervous and endocrine systems.6
Women suffer from IBS more than men do and their symptoms also persist for longer.7 IBS often follows bacterial gastroenteritis, but in many cases the cause of the disease is unknown. Some researchers suggest a chronic low-grade inflammation of the bowel may stimulate an abnormal immune response, thus altering the gastrointestinal physiology and causing the hypersensitivity that underlies IBS.8
Peppermint oil
Peppermint oil (in the form of enteric-coated capsules) has been shown to be effective in IBS patients with non-serious constipation or diarrhoea to alleviate the symptoms of pain and bloating and improve quality of life. In fact, eight out of 12 placebo-controlled trials showed statistically significant effects in favour of peppermint oil with an average response rate of 58 per cent versus 29 per cent for placebo.9
Interestingly, the rate of improvement in IBS symptoms from placebo is consistent across peppermint oil trials and modern targeted pharmaceutical trials alike.10 This highlights that an important aspect to consider when interpreting the results of any IBS trial is that the causes of IBS are complex and as such it is unlikely that any single treatment will have a universal effect.11 In most cases, having a good relationship with your doctor is at least as important as any specific treatment in producing patient satisfaction, adherence to treatment and clinical improvement.12
Adverse effects from peppermint oil include heartburn and anal/perianal burning or discomfort sensations. By comparison, the side-effects typically reported from a class of pharmaceutical drugs called anticholinergics (prescribed for IBS because they relax smooth muscle, thereby reducing spasms or contractions in the gastrointestinal tract) are dry mouth and blurred vision.13
Anticholinergics, and two other new classes of drugs called 5HT3-antagonists (which inhibit the action of serotonin in the gut to decrease colonic transit time) and 5HT4-agonists (which stimulate the action of serotonin in the gut to increase colonic transit time), do not offer increased improvement rates in symptoms compared with peppermint oil. However, 5HT3-antagonists and 5HT4-agonists do appear useful under tight medical supervision in patients with serious diarrhoea or constipation respectively.14
Interestingly, the effect of 5HT3-antagonists and 5HT4-agonists, which work on serotonin receptors in the gut, could help to explain the link between stress or emotional state and IBS. This is because, while 95 per cent of the body’s serotonin resides in the gut, it’s also present in the brain. And, although the subtypes of serotonin receptors in the brain that antidepressants tend to work on are different from those in the gut, the similarities may explain in part why antidepressants can help relieve some IBS symptoms.15 Many practitioners also recognise the importance of stress management and counselling in the treatment of IBS.16
Contraindications: It’s not recommended that peppermint oil be used internally during pregnancy and lactation or in the presence of gallbladder inflammation, severe hepatic disease, gastro-oesophageal reflux disease or bile duct obstruction. It should not be given internally to children.17
Turmeric
Recently, the results of a pilot study evaluating turmeric in the treatment of IBS have proved promising.18 From 500 volunteers, 207 were chosen to participate in the study. The subjects were randomly allocated to receive either one or two 72mg tablets of standardised turmeric extract per day for eight weeks. More than 70 per cent of the participants were female and the majority were over 50 years old.
The researchers found that, at the start of the trial, the prevalence of IBS had already fallen significantly since the time the subjects were recruited. In the group receiving one tablet, the incidence of IBS was 41 per cent lower and in the group receiving two tablets, the incidence of IBS was 57 per cent lower. This was on the first day of the trial before any treatment had begun.
While the researchers speculated that this spontaneous improvement could be due to the fact that the patients were recruited one month before Christmas, which is a stressful time of year, they also noted that the anticipation of being in the trial may have brought improvement in some people.
This correlates well with the high rates of improvement seen from placebo in most IBS clinical trails. Some trials have reported up to 70 per cent improvement from the placebo effect. The figure tends to go down the longer the period of the trial, suggesting higher placebo-response rates may be reflective of greater contact between IBS patients and healthcare professionals.19 This effect makes it difficult to deny that a psychosomatic relationship between emotional state and IBS symptoms exists.
Nevertheless, when the researchers of the turmeric trial conducted an analysis of the participants’ abdominal pain/discomfort scores after the trial had finished, significant reductions in score of 22 per cent and 25 per cent were respectively noted in the one-tablet and the two-tablet groups.
Overall, 67 per cent of the one-tablet group and 70 per cent of the two-tablet group self-reported a definite or some improvement in their IBS after treatment and only one person in each group reported a worsening of symptoms.
Turmeric (Curcuma longa) has been traditionally used in Indian, Chinese and Western herbal medicine for conditions such as poor digestion, abdominal pain and distension. The important chemical compound in turmeric, curcumin, has been shown to possess anti-inflammatory, bile-stimulating, antimicrobial and gas-preventing actions that would be useful in the treatment of IBS.20
Contraindications: It’s not recommended that turmeric be used therapeutically during pregnancy and lactation or in the presence of bile duct obstruction, peptic ulcer, hyperacidity, gallstones or bleeding disorders.21
Probiotics
Another alternative to pharmaceuticals that has been studied extensively in the treatment of IBS is probiotics. Evidence of the benefit, however, is conflicting. Overall, only marginal improvements in flatulence and bloating have been shown. Despite this, a cohort study found that patients who suffered gastroenteritis were 10 times more likely to develop IBS in the 12 months post-infection. In these patients probiotics may have a therapeutic role as they are thought to down-regulate the immune response in the gut following infection.22
Dietary modification
More research is needed to determine the most successful way to treat IBS, but at present the best clinical results are achieved with an individually tailored therapeutic approach. This includes dietary modification.
Dietary modification has been found to play an important role in alleviating the symptoms of IBS in some people. Doctors tend to advise eliminating fermentable carbohydrates such as beans, cabbage, Brussels sprouts, whole grains, fruit, onions and wheat because they are all capable of producing gas after being metabolised by colonic flora and then fermented by the bacteria that inhabit the large intestine. However, the research to support excluding these and sulphur-containing foods such as garlic and meat, which are also thought to cause gas, is limited and not conclusive for the treatment of IBS.23
Malabsorbed fructose (a sugar used to sweeten everything from softdrinks, fruit and sports drinks to baked goods, lollies, jams, yoghurts and all sorts of canned and packaged foods) has also been suggested by researchers to cause altered bowel frequency, bloating, flatus and pain in people who are intolerant. This is because if it’s not absorbed properly, like the carbohydrates mentioned above, fructose can ferment in the large intestine and cause gas.24
Food allergies that stimulate an immunological response can be implicated, too. In one study, this was correlated with a sensitivity response in IBS patients.25
In patients with suspected coeliac disease, eliminating dietary gluten (found in wheat) and gliadin (found in wheat, oats and rye) can alleviate the symptoms of IBS.26 But, as with food allergies, these types of dietary measures tend to work only with those people who have a clearly diagnosable intolerance to an illicit food or foods.
Fat, lactose (milk sugar), coffee and alcohol have all been suggested as possible triggers of IBS symptoms, although the science behind these suggestions is still for the most part speculative. Again, in people who are specifically lactose intolerant, it’s possible to achieve good results by eliminating dairy products. Unfortunately, the symptoms for lactose intolerance and IBS are often indistinguishable. Thus, while it’s worth testing whether IBS symptoms improve in the absence of dairy, there is no guarantee the outcome will be positive.27
Dietary fibre in the form of insoluble fibre supplements such as wheat bran, and soluble fibre supplements such as guar gum, ispaghula and psyllium, have a different effect on different people. Therefore, the results of studies with these treatments are mixed and controversial. In some people taking fibre supplements there is a significant improvement in symptoms, while in others the end result is increased or worsening abdominal bloating and distension.28
The TCM approach
It’s because of the mixed results seen with all these treatments that traditional Chinese medicine (TCM) may generate better results for IBS sufferers than Western therapies. Rather than the one-size-fits-all approach, TCM practitioners suggest a course of action consistent with the distinct overall constitution and individual pattern of symptoms present in each person.29
According to TCM, the spleen is responsible for digestion. However, the spleen is closely linked with the liver, which regulates the flow of qi (energy) around the body. People who suffer from IBS most commonly have an imbalance between the energies of the spleen and liver, but in some cases the kidneys and stomach are involved or a general weakness of the digestive system may be the cause.
In TCM theory, when you feel stressed or angry, the liver energy becomes constrained. It can then start to overbear on the spleen, which becomes weakened. When the spleen is weak, it cannot perform its duties of transforming and transporting fluid. Consequently, this causes bloating, tiredness and diarrhoea. The combination of these symptoms is often referred to as “dampness in the centre”. The “centre” in TCM means the internal centre of the body, which is the digestive system.
Dampness in the body is exacerbated by eating damp-engendering foods and living in a damp environment. Examples of foods that cause dampness include dairy products, raw fruit and vegetables, deepfried or oily foods, very complex grains such as those found in muesli and some wholegrain bread, any foods or drinks that are very cold in temperature, sugary foods and over-processed foods. On the other hand, eating foods that strengthen the spleen helps the spleen to work more effectively to clear the accumulated dampness. Spleen-nourishing foods include Chinese yam, baked root vegetables such as pumpkin, potato and kumera, steamed white rice and chicken.
In people who experience constipation, Chinese medicine often views this as being caused by the constrained liver energy stopping the flow of qi and/or blood through the large intestine. Getting plenty of exercise and reducing stress are critical ways to promote the movement of qi in the body. Among others, herbs such as angelica and peony in the Chinese herbal formula ge xia zhu yu tang can significantly help resolve liver qi stagnation.30
An Australian double-blind, placebo-controlled clinical trial found that with three groups of IBS patients who received placebo, a standardised Chinese herbal formula or an individualised Chinese herbal formula, after 16 weeks both the standardised and the individualised treatments groups had significant improvements in bowel symptom scores compared with the placebo group.31 What was most interesting was that while there was no difference in effectiveness between the two treatment groups, on a 14-week follow-up only the individualised treatment group maintained improvement.
These results show the importance of individualising any IBS treatment regimen but, more importantly, they highlight that the benefits of Chinese medicine are only fully realised with individual consultation with a qualified practitioner.
Why the West?
The occurrence of IBS in Asian countries in general appears to be much lower than in some Western countries like Canada, the UK and Italy, where IBS affects up to 12 per cent of the population. The prevalence figures for Asia range from 5.7 per cent in South China to 8.6 per cent in Singapore. One study in Iran reported a prevalence of 5.8 per cent. Initial theories on why this disparity in IBS prevalence exists between Asia and the West focused on differences in diet. Some researchers suggested the increase in Western food consumption in Asian countries could explain why the prevalence of IBS is increasing globally.32
However, recent analysis of the studies which supported the Western diet theory has found that the results are inconsistent and some of the research is methodologically flawed.33
It’s now speculated, though not fully tested, that a high childhood exposure to infection, rather than high-residue diet, is responsible for the low prevalence of IBS in underdeveloped countries. Being exposed to a variety of micro-organisms early in life could help develop broad immune tolerance, which would enable the intestinal epithelium to respond more efficiently during an episode of gastroenteritis. As a result, symptoms resolve more quickly.34
In the West, where we grow up in the hygienic environment associated with improved socioeconomic conditions, our intestinal immune system remains relatively naive in the face of gastroenteritis later in life, which would result in a greater inflammatory disturbance. This, together with psychological and behavioural factors, may predispose us to the persistence of symptoms manifesting as IBS.35
A further exacerbating factor for the increased rates of IBS in newly developed countries could be the increased stress and decreased exercise associated with the adoption of a Westernised, technology-driven lifestyle.
In summary, at present, the best way to manage IBS is to maintain an all-round healthy lifestyle that includes adequate exercise and stress relief, in conjunction with a positive relationship with your healthcare provider, who can prescribe you an individually tailored treatment regime.
References
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13. Grigoleit and Grigoleit.
14. Drossman, 2004. Grigoleit and Grigoleit.
15. “Serotonin and IBS,” Participate (Winter 2000), www.aboutibs.org/Publications/serotonin.html.
16. JD McGuire and PA Towers, J Complement Med 5, no 1 (Jan/Feb 2006): 12-25.
17. L Skidmore-Roth, Mosby’s Handbook of Herbs & Natural Supplements, 3rd ed (St Louis, Missouri: Elsevier Mosby, 2006).
18. Bundy et al.
19. McGuire and Towers.
20. Bundy et al.
21. L Skidmore-Roth.
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23-6. McGuire and Towers.
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28. McGuire and Towers.
29. Bundy et al.
30-1. McGuire and Towers.
32-5. Gwee.
Kizzy Gandy (BHSc, Chinese herbal medicine) works in regulatory affairs consultancy for complementary medicines and previously worked as a herbalist.
