IRRITABLE BOWEL SYNDROME

In gastroenterology, 'irritable bowel syndrome' ('IBS') or 'spastic colon' is a functional bowel disorder characterized by abdominal pain and changes in bowel habits which are not associated with any abnormalities seen on routine clinical testing. It is fairly common and makes up 20–50% of visits to gastroenterologists. Lower abdominal pain, and bloating associated with alteration of bowel habits and abdominal discomfort relieved with defecation are the most frequent symptoms. The abdominal pain type is usually described in a patient as either diarrhea-predominant ('IBS-D'), constipation-predominant ('IBS-C') or IBS with alternating stool pattern ('IBS-A'). In some individuals, IBS may have an acute onset and develop after an infectious illness characterised by two or more of the following: fever, vomiting, acute diarrhea, positive stool culture. This post-infective syndrome has consequently been termed "post-infectious IBS" ('IBS-PI') and is acute onset Rome II criteria positive. This condition is more homogeneous, being mostly IBS-D and is drawing much clinical investigation.
Chronic functional abdominal pain (CFAP) is quite similar to, but less common than IBS. CFAP can be diagnosed if there is no change in bowel habits.
Because of the name, IBS can be confused with inflammatory bowel disease (IBD).

Symptoms

The symptoms of IBS are abdominal pain in association with diarrhea, constipation, or a change in bowel habits. ^[1]

Diagnosis

The underlying biochemical cause of IBS is not well established, so there is no specific laboratory test which can be performed to diagnose this condition.^[2] Diagnosis of IBS involves excluding conditions which produce with IBS-like symptoms, and then following a procedure to categorize the patient's symptoms.
Because there are many causes of diarrhea and IBS-like symptoms, the American Gastroenterological Association has published a set of guidelines for tests to be performed to diagnose other conditions which may have symptoms similar to IBS. These include gastrointestinal infections, lactose intolerance and celiac disease. Research has suggested that these guidelines are not always followed. ² Once other causes have been excluded, the diagnosis of IBS is performed using a diagnostic algorithm. Well-known algorithms include the Manning Criteria, the Rome I Criteria, the Rome II Process, the Kruis Criteria, and studies have compared their reliability.^[3] The more recent Rome III Process was published in 2006. Physicians may choose to use one of these criteria, or may use other guidelines based on their own experience and the patient's history. The algorithm may include additional tests to guard against mis-diagnosis of other diseases as IBS. Such "red flag" symptoms may include weight loss, GI bleeding, anemia, or nocturnal symptoms. However, researchers have noted that red flag conditions may not always contribute to accuracy in diagnosis — for instance, as many as 31% of IBS patients have blood in their stool.³
The diagnostic algorithm identifies a name which can be applied to the patient's condition based on the combination of the patient's symptoms of diarrhea, abdominal pain, and constipation. For example, the statement "50% of returning travelers had developed functional diarrhea while 25% had developed IBS" would mean that half the travelers had diarrhea while a quarter had diarrhea with abdominal pain. While some researchers believe this categorization system will help physicians understand IBS, others have questioned the value of the system and suggested that all IBS patients have the same underlying disease but with different symptoms.^[4]

Misdiagnosis

Anecdotal accounts exist of poor patient outcomes due to treatable causes of diarrhea being mis-diagnosed as IBS. Common examples include infectious diseases, celiac disease,^[5] and lactose intolerance.^[6] See 'List of causes of diarrhea' for other conditions which can cause diarrhea.

Medical conditions that accompany IBS

Researchers have identified several medical conditions, or comorbidities, which appear with greater frequency in patients diagnosed with IBS.
:'Headache, Fibromyalgia, and Depression':A study of 97,593 individuals with IBS identified comorbidities as headache, fibromyalgia, and depression. ^[7] Fibromyalgia has also been identified in other studies as a co-morbidity of IBS. ^[8]^[9]
:'Inflammatory Bowel Disease': Some researchers have suggested that IBS is a type of low-grade inflammatory bowel disease.^[10] Researchers have suggested that IBS and IBD are interrelated diseases,^[11] noting that patients with IBD experience IBS-like symptoms when their IBD is in remission. ^[12] ^[13] A 3-year study found that patinets diagnosed with IBS were 16.3 times more likely to develop IBD during the study period. ^[14] Serum markers associated with inflammation have also been found in patients with IBS (see Causes).
:'Endometriosis': One study has reported a statistically significant link between migraine headaches, IBS, and endometriosis. ^[15]

Causes of IBS

IBS as a psychosomatic illness (1950- ~2000)

''Most peptic ulcers are now treated with 1-2 weeks of antibiotic therapy, since it has been discovered that they are caused by a combination of a genetic trait in the patient and infection with the bacteria H. Pylori.''^[16]

One of the first references to the concept of an "Irritable Bowel" appeared in the Rocky Mountain Medical Journal in 1950. ^[17] The term was used to categorize patients who developed symptoms of diarrhea, abdominal pain, constipation, but where no well-recognized infective cause can could be found. Early theories suggested that the Irritable Bowel was caused by a somatic, or mental disorder. One paper from the 1980s investigated "learned illness behavior" in patients with IBS and peptic ulcers. ^[18] Another study suggested that both IBS and peptic ulcer patients would benefit from 15 months of psychotherapy ^[19].
Additional publications suggesting the role of brain-gut "axis" appeared in the 1990s. ^[20] A 1997 study published in ''Gut'' magazine described the "derailing of the brain-gut axis" in association with IBS. ^[21]

Discovery of inflammation and secretory changes (1997- )

In the late 1990s and later, research publications began identifying specific biochemical changes present in tissue biopsies and serum samples from IBS patients, suggesting that the symptoms of IBS may have an organic rather than psychosomatic cause. These studies identified cytokines and secretory products in tissues taken from IBS patients. Cytokines are chemicals produced by the body to perform communication between cells. The cytokines identified in IBS patients are inflammatory cytokines which are associated with the body's immune response.

★ A 1997 study of blood samples from IBS patients found elevated levels antibodies to the protozoan ''Blastocystis''. The study was conducted at Aga Khan University in Pakistan and published in the ''American Journal of Tropical Medicine and Hygiene'' ^[22]

★ A 2001 study showed that intestinal biopsies from patients with constipation predominant IBS secreted higher levels of serotonin in-vitro. ^[23] The study was conducted at the International Medical University (Japan) and published in ''Digestion.'' Serotonin controls smooth muscle contraction in the body, and many other functions. Serotonin is secreted by some gastrointestinal protozoa, causing diarrhea and elevated serum serotonin levels in humans. ^[24]^[25]^[26]

★ A 2003 study of rectal biopsy tissue from IBS patients showed increased levels of cellular structures involved in the production of the inflammatory cytokine Interleukin-1 Beta. ^[27] The study was conducted at the National University of Singapore and published in ''Gut'' magazine

★ A 2007 study of blood samples from IBS patients identified elevated levels of cytokines TNF-Alpha, Interleukin-1, and Interleukin-6 in patients with IBS.^[28] The study was conducted at the University of Adelaide, Australia and published in ''Gastroenterology''

★ A 2007 study of intestinal biopsies from IBS patients showed increased levels of protease secretion. Proteases are chemicals which split proteins into smaller molecules. The human body uses them to digest proteins, and they are also used by infectious diseases to combat the host's immune system. ^[29] The study was performed at the University of Calgary and published in the ''Journal of Clinical Investigation.''

Identification of active infections (2003- )

Some researchers believe IBS may be caused by an active infection which has not yet been discovered. Many clinically significant gastrointestinal pathogens have been discovered in the last 50 years, and medical recognition has taken decades in some cases (see History of emerging infectious diseases). Most recently, a study has found that the antibiotic Rifaximin provides sustained relief for IBS patients. ^[30]

Some physicians retain the view that no infectious cause exists, and suggest that IBS patients have too much bacteria in their intestines and the antibiotics reduce the amount of bacteria. This theory is known as SIBO (Small Intestinal Bacterial Overgrowth).^[31]

Protozoal Infections

Protozoa are single-celled organisms which can cause symptoms equivalent to IBS. ^[32] Several researchers have focused on unrecognized protozoal infection as a cause of IBS because of this, and because some protozoal infections occur at a statistically significant rate in IBS patients.^[33] ^[34] The two protozoa investigated have a high prevalence in industrialized countries, infect the bowel, but are recently emerged pathogens so little is known about them.
'''Blastocystis''' is a single-celled organism which has been reported to produce symptoms of abdominal pain, constipation and diarrhea in patients, along with headaches and depression. ^[35] Researchers have noted that existing methods may fail to diagnose infection properly ^[36], and it may not respond to treatment with common antiprotozoals. ^[37]^[38]^[39]^[40] The following reports have linked ''Blastocystis'' infection to IBS:

★ A study of IBS patients in the Middle East found 43% were infected with ''Blastocystis'' vs. 7% of healthy controls. ³³.

★ An additional study of IBS patients in the Middle East showed a "significantly increased" immune reaction in IBS patients to ''Blastocystis'', even when the organism could not be identified in stool samples.²²

★ A European study compared ''Blastocystis'' infection rates in IBS patients to those of healthy controls and found a statistically significant infection rate in IBS patients. ³⁴

★ Early reports from the US physicians in the 1980s suggested the presence of the organism was not relevant to the diagnostic process, and patients infected with ''Blastocystis'' could be diagnosed with IBS. ^[39]

Prevalence of protozoal infections in industrialized countries (United States and Canada) in 21st century. ⁴⁷ ^[42]

Since the 1980s, researchers have found multiple types of ''Blastocystis'' infect humans, and some types cause disease while others do not, possibly explaining conflicting reports of physicians.^[43] Three studies of experimental infection of animals with ''Blastocystis'' report fulfilling Koch's Postulates, a widely accepted criteria for establishing the ability of an organism to cause disease. ^[44]^[45]^[46]
'''Dientamoeba fragilis''' is a single-celled organism which produces abdominal pain and diarrhea. Studies have reported a high incidence of infection in developed countries, and symptoms of patients resolve following antibiotic treatment. ^[47]^[48] One study reported on a large group of patients with IBS-like symptoms who were found to be infected with ''Dientamoeba fragilis'', and experienced resolution of symptoms following treatment. ^[49] Researchers have noted that methods used clinically may fail to detect some ''Dientamoeba fragilis'' infections. ⁴⁸

Treatment

A questionnaire in 2006 designed to identify patients’ perceptions about IBS, their preferences on the type of information they need, as well as educational media and expectations from health care providers, revealed misperceptions about IBS developing into other conditions, including colitis, malnutrition, and cancer.^[50]
The survey found IBS patients were most interested in learning about foods to avoid (60%), causes of IBS (55%), medications (58%), coping strategies (56%), and psychological factors related to IBS (55%). The respondents indicated that they wanted their physician to be available via phone or e-mail following a visit (80%), have the ability to listen (80%), and provide hope (73%) and support (63%).

Diet

There are a number of dietary changes a person with IBS can make to prevent the overreaction of the gastrocolic reflex and lessen pain, discomfort, and bowel dysfunction. Having soluble fiber foods and supplements, substituting soy or rice products for milk products, being careful with fresh fruits and vegetables that are high in insoluble fiber, and eating frequent meals of small amounts of food, can all help to lessen the symptoms of IBS. Foods and beverages to be avoided or minimized include red meat, oily or fatty and fried products, milk products (even when there is no lactose intolerance), solid chocolate, coffee (regular and decaffeinated), alcohol, carbonated beverages, especially those containing sorbitol or other artificial sweeteners. Care, however, should be taken to avoid adding foods to the diet to which the patient is allergic or intolerant.^[51]
Definitive determination of dietary issues can be accomplished by testing for the physiological effects of specific foods. The ELISA food allergy panel can identify specific foods to which a patient has a reaction. Other testing can determine if there are nutritional deficiencies secondary to diet that may also play a role. Removal of foods causing IgG immune response as measured using the ELISA food panel has been shown to substantially decrease symptoms of IBS in several studies.^[52]
There is no evidence that digestion of food or absorption of nutrients is problematic for those with IBS at rates different from those without IBS. However, the very act of eating or drinking can provoke an overreaction of the gastrocolic response in some patients with IBS due to their heightened visceral sensitivity, and this can lead to abdominal pain, diarrhea, and/or constipation.^[53]
Several of the most common dietary triggers are well-established by clinical studies at this point; research has shown that IBS patients are hypersensitive to fats and fructose.
^[54] ^[55]
It also appears that some foods are more difficult for the gut as evidenced by elevated food-specific IgG4 antibodies being present,^[56]
^[57] while others increase colonic contractions, which may be painful, due to increased visceral sensitivity in IBS sufferers.
^[58]
;Fiber:
In patients who do ''not'' have diarrhea predominant irritable bowel, soluble fiber at doses of 20 grams per day can reduce overall symptoms but will not reduce pain. The research supporting dietary fiber contains conflicting, small studies that are complicated by the heterogeneity of types of fiber and doses used Systematic review: the role of different types of fibre in the treatment of irritable bowel syndrome., Bijkerk C, Muris J, Knottnerus J, Hoes A, de Wit N, , , Aliment Pharmacol Ther, 2004 . The one meta-analysis that controlled for solubility found that only soluble fiber improved global symptoms of irritable bowel and neither type of fiber reduced pain .. Positive studies have used 20-30 grams per day of psyllium seed (also called ispaghula husk) Double blind study of ispaghula in irritable bowel syndrome., Prior A, Whorwell P, , , Gut, 1987 Ispaghula therapy in irritable bowel syndrome: improvement in overall well-being is related to reduction in bowel dissatisfaction., Jalihal A, Kurian G, , , J Gastroenterol Hepatol, . One study specifically examined the effect of dose and found that 20 grams of ispaghula husk was better than 10 grams and equivalent to 30 grams per day Optimum dosage of ispaghula husk in patients with irritable bowel syndrome: correlation of symptom relief with whole gut transit time and stool weight., Kumar A, Kumar N, Vij J, Sarin S, Anand B, , , Gut, 1987 An uncontrolled study noted increased symptoms with insoluble fibers. ^[59] It is unclear if these symptoms are truly increased compared to a control group. If the symptoms are increased, it is unclear if these patients were diarrhea predominant (which can be exacerbated by fiber Role of loperamide and placebo in management of irritable bowel syndrome (IBS)., Cann P, Read N, Holdsworth C, Barends D, , , Dig Dis Sci, 1984 What is the benefit of coarse wheat bran in patients with irritable bowel syndrome?, Cann P, Read N, Holdsworth C, , , Gut, 1984 ), or if the increase is temporary before benefit occurs. There is a mistaken presumption that fiber therapy only works for those with consipation. In actuality fiber can act as a counterbalance to both constipation, by retaining water in the bowel, and for diarreah, by absorbing excess water.

Medication

Initial treatments

Medications may consist of stool softeners and laxatives in constipation-predominant IBS, and antidiarrheals (e.g., opioid or opioid analogs such as loperamide (Imodium®), diphenoxylate (Lomotil®)) or Codeine in diarrhea-predominant IBS for mild symptoms Bulking agents, antispasmodic and antidepressant medication for the treatment of irritable bowel syndrome., Quartero A, Meineche-Schmidt V, Muris J, Rubin G, de Wit N, , , Cochrane Database Syst Rev, Meta-analysis: The treatment of irritable bowel syndrome., Lesbros-Pantoflickova D, Michetti P, Fried M, Beglinger C, Blum A, , , Aliment Pharmacol Ther, 2004 Pharmacologic treatment of the irritable bowel syndrome: a systematic review of randomized, controlled trials., Jailwala J, Imperiale T, Kroenke K, , , Ann Intern Med, 2000 .

Anti-diarrheal agents

Randomized controlled trials have shown loperamide reduces diarrhea with an inconsistent effect on pain A double-blind placebo-controlled trial with loperamide in irritable bowel syndrome., Efskind P, Bernklev T, Vatn M, , , Scand J Gastroenterol, 1996 .

Laxatives

Main articles: laxative

Regarding laxatives for patients who do not adequately respond to fiber, osmotic agents (polyethylene glycol, sorbitol, and lactulose) are good choices in order to avoid 'cathartic colon' which has been associated with stimulant laxatives Alterations in colonic anatomy induced by chronic stimulant laxatives: the cathartic colon revisited., Joo J, Ehrenpreis E, Gonzalez L, Kaye M, Breno S, Wexner S, Zaitman D, Secrest K, , , J Clin Gastroenterol, 1998 . Among the osmotic laxatives, 17 to 26 grams/day of polyethylene glycol (PEG) has been well studied.

Antispasmodics

The use of antispasmodic drugs (e.g. anticholinergics such as hyoscyamine or dicyclomine) may help patients, especially those with cramps or diarrhea. A meta-analysis by the Cochrane Collaboration concludes that if 6 patients are treated with antispasmodics, 1 patient will benefit (number needed to treat = 6)used. Antispasmodic drugs are also available in combination with tranquilizers or barbiturates, such as Librax® (chlordiazepoxide and clidinium) and Donnatal® (mixed salts of belladonna alkaloids and phenobarbital), respectively. However, the value of the combination therapies is not clear as the role of tranquilizers is not established.

Drugs affecting serotonin (5-HT)

Drugs affecting serotonin (5-HT) in the intestines can help reduce symptoms Serotoninergic neuroenteric modulators., Talley N, , , Lancet, 2001 . Serotonin stimulates the gut motility and so agonists can help constipation predominate irritable bowel while antagonists can help diarrhea predominant irritable bowel:

Agonists

★ Tegaserod, a selective 5-HT4 agonist for IBS-C, is available for relieving IBS constipation in women and chronic idiopathic constipation in men and women. On March 30, 2007, the Food and Drug Administration (FDA) requested that Novartis Pharmaceuticals voluntarily discontinue marketing of Zelnorm (tegaserod) based on the recently identified finding of an increased risk of serious cardiovascular adverse events (heart problems) associated with use of the drug. Novartis agreed to voluntarily suspend marketing of the drug in the United States and in many other countries. On July 27, 2007 the Food and Drug Administration (FDA) approved a limited treatment IND program for Zelnorm in the USA to allow restricted access to the medication for patients in need if no comparable alternative drug or therapy is available to treat the disease. The USA FDA had issued two previous warnings about the serious consequences of Tegaserod. In 2005, Tegaserod was rejected as an IBS medication by the European Union. Tegaserod, marketed as Zelnorm in the United States, was the only agent approved to treat the multiple symptoms of IBS (in women only), including constipation, abdominal pain and bloating. A meta-analysis by the Cochrane Collaboration concludes that if 17 patients are treated with typical doses of tegaserod, 1 patient will benefit (number needed to treat = 17) Tegaserod for the treatment of irritable bowel syndrome., Evans B, Clark W, Moore D, Whorwell P, , , Cochrane Database Syst Rev, .

★ Selective serotonin reuptake inhibitor anti-depressants (SSRIs), because of their serotonergic effect, would seem to help IBS, especially patients who are constipation predominant. Initial crossover studies A controlled crossover study of the selective serotonin reuptake inhibitor citalopram in irritable bowel syndrome., Tack J, Broekaert D, Fischler B, Oudenhove L, Gevers A, Janssens J, , , Gut, 2006 and randomized controlled trials The effect of fluoxetine in patients with pain and constipation-predominant irritable bowel syndrome: a double-blind randomized-controlled study., Vahedi H, Merat S, Rashidioon A, Ghoddoosi A, Malekzadeh R, , , Aliment Pharmacol Ther, 2005 The cost-effectiveness of psychotherapy and paroxetine for severe irritable bowel syndrome., Creed F, Fernandes L, Guthrie E, Palmer S, Ratcliffe J, Read N, Rigby C, Thompson D, Tomenson B, , , Gastroenterology, 2003 Paroxetine to treat irritable bowel syndrome not responding to high-fiber diet: a double-blind, placebo-controlled trial., Tabas G, Beaves M, Wang J, Friday P, Mardini H, Arnold G, , , Am J Gastroenterol, 2004 support this role.

Antagonists

★ Alosetron, a selective 5-HT3 antagonist for IBS-D, which is only available for women in the United States under a restricted access program, due to severe risks of side-effects if taken mistakenly by IBS-A or IBS-C sufferers.

★ Cilansetron, also a selective 5-HT3 antagonist, is undergoing further clinical studies in Europe for IBS-D sufferers. In 2005, Solvay Pharmaceuticals withdrew Cilansetron from the United States regulatory approval process after receiving a "not approvable" action letter from the FDA requesting additional clinical trials.

Other agents

Anti-depressents include both tricyclic antidepressants (TCAs) and the newer selective serotonin reuptake inhibitors (SSRIs). In addition to improving symptoms via treating any co-existing depression, TCAs have anti-cholinergic actions while SSRIs are serotonergic. Thus in theory, TCAs would best treat diarrhea-predominant IBS while SSRIs would best treat constipation-predominant IBS. A meta-analysis of randomized controlled trials of mainly TCAs found 3 patients have to be treated with TCAs for one patient to improve (number needed to treat = 3) Treatment of functional gastrointestinal disorders with antidepressant medications: a meta-analysis., Jackson J, O'Malley P, Tomkins G, Balden E, Santoro J, Kroenke K, , , Am J Med, 2000 . A separate randomized controlled trial found that TCAs are best for patients with diarrhea-predominant IBS Cognitive-behavioral therapy versus education and desipramine versus placebo for moderate to severe functional bowel disorders., Drossman D, Toner B, Whitehead W, Diamant N, Dalton C, Duncan S, Emmott S, Proffitt V, Akman D, Frusciante K, Le T, Meyer K, Bradshaw B, Mikula K, Morris C, Blackman C, Hu Y, Jia H, Li J, Koch G, Bangdiwala S, , , Gastroenterology, 2003 . SSRIs are discussed above under 'Drugs affecting serotonin'.
Recent studies have suggested that rifaximin, a non-absorbable antibiotic, can be used as an effective treatment for abdominal bloating and flatulence ^[60] The effect of a nonabsorbed oral antibiotic (rifaximin) on the symptoms of the irritable bowel syndrome: a randomized trial., Pimentel M, Park S, Mirocha J, Kane S, Kong Y, , , Ann Intern Med, 2006 , giving more credibility to the potential role of bacterial overgrowth in some patients with IBS ^[61].
A double-blind, randomized, placebo-controlled trial compared the multi-herbal extract Iberogast versus placebo in the treatment of all three forms of irritable bowel syndrome. This multi-target phytopharmaceutical was found to be significantly superior to placebo via both an abdominal pain scale (p value = 0.0009) and an IBS symptom score (p value = 0.001) after four weeks of treatment.^[62]
Enteric coated peppermint oil capsules has been advocated for IBS symptoms in adults and children ^[63]; however, results from trials have been inconsistent Peppermint oil does not relieve the pain of irritable bowel syndrome., Nash P, Gould S, Bernardo D, , , Br J Clin Pract, 1986 Enteric-coated peppermint-oil capsules in the treatment of irritable bowel syndrome: a prospective, randomized trial., Liu J, Chen G, Yeh H, Huang C, Poon S, , , J Gastroenterol, 1997 . Peppermint may exacerbate gastroesophageal reflux disease.
For severe diarrhea-predominant IBS, more potent opioids may be used, such as codeine or propoxyphene (Darvon®); refractory cases may even be treated with paregoric, or, more rarely, deodorized tincture of opium or morphine sulfate. The use of opioids remains controversial due to the lack of evidence supporting their benefit and the potential risk of tolerance, physical dependence and psychological dependence (addiction).
Cannabis has theoretical support for its role The endocannabinoid system in the physiology and pathophysiology of the gastrointestinal tract., Massa F, Storr M, Lutz B, , , J Mol Med, 2005 Clinical endocannabinoid deficiency (CECD): can this concept explain therapeutic benefits of cannabis in migraine, fibromyalgia, irritable bowel syndrome and other treatment-resistant conditions?, Russo E, , , Neuro Endocrinol Lett, , but has not been subject of clinical studies. Although illegal in many counties, it has been prescribed to patients in nations such as Canada. Some of the argued benefits of cannabis are the reduction of pain and nausea, appetite stimulation, and assisting in falling asleep.
Amitiza (lubiprostone), currently indicated for chronic idiopathic constipation, was submitted on July 12, 2007 to the United States Food and Drug Administration (FDA) as a New Drug Application to treat IBS with constipation (IBS-C).

New Drugs Under Development

New drugs are currently under development for IBS. New drug therapy for IBS often includes clinical trials for a period of time to determine if it is effective in treating IBS symptoms while monitoring the drug for safety and tolerance.

Psychotherapy and hypnotherapy

There is a strong brain-gut component to IBS, and cognitive therapy may improve symptoms in a proportion of patients in conjunction with antidepressants ^[64]. In a randomized controlled trial of referred patients, cognitive behavioral therapy helped even though patients in this study ''did not'' have any psychiatric diagnoses The combination of medical treatment plus multicomponent behavioral therapy is superior to medical treatment alone in the therapy of irritable bowel syndrome., Heymann-Mönnikes I, Arnold R, Florin I, Herda C, Melfsen S, Mönnikes H, , , Am J Gastroenterol, 2000 .
Gut-directed or gut-specific hypnotherapy or self-hypnosis is one of the most promising areas of IBS treatment. An uncontrolled study shows that symptom reduction/elimination from IBS hypnotherapy can last at least five years ^[65].
Relaxation therapy in four 90 minute group sessions was found to help in an randomized controlled trial.^[66]

Alternative treatments

;Probiotics:
Probiotics are generally accepted to be potentially beneficial strains of bacteria and yeast, often found in the human gut. One research study has shown a clear link between the ingestion of Lactobacillus plantarum LP299V and sufferers of IBS who reported resolution of their abdominal pain ^[67]. Another study showed the utility of B. infantis 35625, a strain of Bifidobacteria, in normalizing bowel movement frequency in sufferers of IBS ^[68]. Some practitioners of Integrative Medicine now recommend a strain of Lactobacillus known commonly as "LGG" after its discoverers Gorbach and Goldin. This strain in particular has shown an ability to endure the acidic environment of the stomach and survive until presentation to the intestinal tract ^[69].
A prospective placebo-controlled study found patients with diarrhea predominant IBS taking ''Saccharomyces boulardii'', a probiotic yeast, had a significant reduction on the number and improvement in consistency of bowel movements.^[70]
;Acupuncture:
Many sufferers of IBS seek relief using Acupuncture, a component of Traditional Chinese Medicine. The meta-analysis by the Cochrane Collaboration concluded 'Most of the trials included in this review were of poor quality and were heterogeneous in terms of interventions, controls, and outcomes measured. With the exception of one outcome in common between two trials, data were not combined. Therefore, it is still inconclusive whether acupuncture is more effective than sham acupuncture or other interventions for treating IBS' Acupuncture for treatment of irritable bowel syndrome., Lim B, Manheimer E, Lao L, Ziea E, Wisniewski J, Liu J, Berman B, , , Cochrane Database Syst Rev, . One practitioner of Tradtional Chinese Medicine asserts that IBS has become a bit of a "garbage diagnosis" for some medical practitioners. Traditional Chinese Medicine does not recognize the Western diagnosis of IBS per se, as the named condition has no definitive single test for diagnosis, clear cause, or cure. Traditional Chinese Medicine approaches IBS on an individual symptom-by-symptom basis, rather than recognizing a standard "IBS" diagnosis, which then warrants a blanket "IBS" treatment ^[71]. According to the National Institutes of Health, "Preclinical studies have documented acupuncture's effects, but they have not been able to fully explain how acupuncture works within the framework of the Western system of medicine that is commonly practiced in the United States." ^[72].

Geographics

Percentage of Population Reporting Symptoms of IBS in Various Studies from Various Geographic Regions - see table for references

'By Country': Studies have reported that the prevalence of IBS varies by country and by age range examined. The following table contains a list of studies performed in different countries that measured the prevalence of IBS and IBS-like symptoms:

Percentage of Population Reporting Symptoms of IBS in Various Studies from Various Geographic Areas
Country	Prevalence	Author/Year	Notes
Canada	6% ^[73]	Boivin,2001
Japan	10%^[74]	Quigley,2006	Study measured prevalence of GI abdominal pain/cramping
United Kingdom	8.2% ^[75]10.5%	United States	15% ⁷³	Boivin,2001	Estimate
Pakistan	14%^[76]	Jafri, 2007	Much more common in 16-30 age range. Of IBS patients, 56% male, 44% female
Pakistan	34%^[77]	Jafri,2005	College students
Mexico City	35% ^[78]	Schmulson, 2006	n=324. Also measured functional diarrhea and functional vomiting. High rates attributed to "stress of living in a populated city."
Brazil	43% ⁷⁴	Quigley,2006	Study measured prevalence of GI abdominal pain/cramping
Mexico	46%⁷⁴	Quigley,2006	Study measured prevalence of GI abdominal pain/cramping

'Returning Travelers': A study of United States residents returning from international travel found a high rate of IBS and persistent diarrhea which developed during travel and persisted upon return. The study examined 83 subjects in Utah, most of whom were returning missionaries. Of the 68 who completed the gastrointestinal questionnaire, 27 reported persistent diarrhea that developed while traveling, and 10 reported persistent IBS that developed while traveling. ^[79]

Economic cost of IBS

The aggregate cost of irritable bowel syndrome in the United States has been estimated at $1.7-$10 billion in direct medical costs, with an additional $20 billion in indirect costs, for a total of $21.7-$30 billion. {{ The burden of illness of irritable bowel syndrome: current challenges and hope for the future., Hulisz D., , , J Manag Care Pharm., 2004 A study by a managed care company comparing medical costs of IBS patients to non-IBS controls identified a 49% annual increase in medical costs associated with a diagnosis of IBS.^[80] A 2007 study from a managed care oganization found that IBS patients incurred average annual direct costs of $5,049 and $406 in out-of-pocket expenses. ^[81]

Research spending on IBS

The National Institutes of Health provides a searchable database for grant awards since 1974 on its CRISP database, and provides dollar amounts for recent awards on its Intramural Grant Award Page.
In 2006, the NIH awarded approximately 56 grants related to IBS, totalling approximately $18,787,710.

Prognosis

IBS is not fatal nor is it linked to the development of other serious bowel diseases. However, due to the chronic pain, discomfort, and other symptoms, work absenteeism, social phobias, and other negative quality-of-life effects can be common in more serious cases.

References

1. Diagnostic approach to the patient with irritable bowel syndrome, Schmulson MW, Chang L, , , Am. J. Med., 1999
2. Do published guidelines for evaluation of irritable bowel syndrome reflect practice?, Yawn BP, Lydick E, Locke GR, Wollan PC, Bertram SL, Kurland MJ, , , BMC gastroenterology, 2001
3. Evidence- and consensus-based practice guidelines for the diagnosis of irritable bowel syndrome, Fass R, Longstreth GF, Pimentel M, ''et al'', , , Arch. Intern. Med., 2001
4. A unifying hypothesis for the functional gastrointestinal disorders: really multiple diseases or one irritable gut?, Talley NJ, , , Reviews in gastroenterological disorders, 2006
5. Testing for celiac sprue in irritable bowel syndrome with predominant diarrhea: a cost-effectiveness analysis, Spiegel BM, DeRosa VP, Gralnek IM, Wang V, Dulai GS, , , Gastroenterology, 2004
6. Lactose malabsorption and irritable bowel syndrome. Effect of a long-term lactose-free diet, Vernia P, Ricciardi MR, Frandina C, Bilotta T, Frieri G, , , The Italian journal of gastroenterology, 1995
7. Migraine, fibromyalgia, and depression among people with IBS: a prevalence study, Cole JA, Rothman KJ, Cabral HJ, Zhang Y, Farraye FA, , , BMC gastroenterology, 2006
8. Prevalence of irritable bowel syndrome and depression in fibromyalgia, Kurland JE, Coyle WJ, Winkler A, Zable E, , , Dig. Dis. Sci., 2006
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External links

★ The IBS Network

★ Rome II Diagnostic Criteria for the Functional Gastrointestinal Disorders

★ Irritable bowel syndrome at informedhealthonline.org

★ Women at higher risk for IBS

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