46-540: Irritable bowel syndrome ( IBS ) is a functional gastrointestinal disorder characterized by a group of symptoms that commonly include abdominal pain , abdominal bloating and changes in the consistency of bowel movements . These symptoms may occur over a long time, sometimes for years. IBS can negatively affect quality of life and may result in missed school or work or reduced productivity at work. Disorders such as anxiety , major depression , and chronic fatigue syndrome are common among people with IBS. The cause of IBS
92-684: A gluten-free diet of immune-mediated symptoms, including autoimmune diseases, once having reasonably ruled out celiac disease and wheat allergy , is another way to realize a differential diagnosis. People with IBS are at increased risk of being given inappropriate surgeries such as appendectomy , cholecystectomy , and hysterectomy due to being misdiagnosed as other medical conditions. Some common examples of misdiagnosis include infectious diseases , coeliac disease , Helicobacter pylori , parasites (non- protozoal ). The American College of Gastroenterology recommends all people with symptoms of IBS be tested for coeliac disease. Bile acid malabsorption
138-576: A bulking agent, and for many people with IBS-D, allows for a more consistent stool. For people with IBS-C, it seems to allow for a softer, moister, more easily passable stool. However, insoluble fiber (e.g., bran ) is not effective for IBS. In some people, insoluble fiber supplementation may aggravate symptoms. Fiber might be beneficial in those who have a predominance of constipation. In people who have IBS-C, soluble fiber can reduce overall symptoms but will not reduce pain. The research supporting dietary fiber contains conflicting small studies complicated by
184-403: A common presentation, and testing for these conditions would yield low numbers of positive results, so it is considered difficult to justify the expense. Conditions that may present similarly include celiac disease, bile acid malabsorption , colon cancer, and dyssynergic defecation . Ruling out parasitic infections, lactose intolerance , small intestinal bacterial overgrowth, and celiac disease
230-399: A family history of the condition are more likely to develop IBS. Further risk factors are anxiety , depression , and stress . The risk of developing IBS increases six-fold after having a gastrointestinal infection ( gastroenteritis ). This is also called post-infectious IBS . The risk of developing IBS following an infection is further increased in those who also had a prolonged fever during
276-451: A feeling of incomplete evacuation ( tenesmus ) or bloating. In some cases, the symptoms are relieved by bowel movements . People with IBS, more commonly than others, have gastroesophageal reflux , symptoms relating to the genitourinary system , fibromyalgia , headache , backache , and psychiatric symptoms such as depression, sleep disorders, and anxiety . About a third of adults who have IBS also report sexual dysfunction , typically in
322-578: A good doctor–patient relationship are an important part of care. About 10–15% of people in the developed world are believed to be affected by IBS. The prevalence varies according to country (from 1.1% to 45.0%) and criteria used to define IBS; however the average global prevalence is 11.2%. It is more common in South America and less common in Southeast Asia . In the Western world , it
368-1132: A lower certainty of evidence. Physical activity could significantly improve people’s adherence and, consequently, lead to a significant clinical benefit for symptoms of irritable bowel syndrome. Medications that may be useful include antispasmodics such as dicyclomine and antidepressants . Both H1- antihistamines and mast cell stabilizers have shown efficacy in reducing pain associated with visceral hypersensitivity in IBS. A number of 5-HT3 antagonists or 5-HT4 agonists were proposed clinically to treat diarrhea-predominant IBS and constipation-predominant IBS, respectively. However, severe side effects have resulted in its withdrawal by food and drug administration and are now prescribed under emergency investigational drug protocol. Other 5-HT receptor subtypes, such as 5-HT7 receptor , have yet to be developed. For people who do not adequately respond to dietary fiber, osmotic laxatives such as polyethylene glycol , sorbitol , and lactulose can help avoid "cathartic colon" which has been associated with stimulant laxatives. Lubiprostone
414-466: A novel 5-HT 7 receptor antagonist administered by mouth reduced intestinal pain levels. Abnormalities occur in the gut flora of individuals who have IBS, such as reduced diversity, a decrease in bacteria belonging to the phylum Bacteroidota , and an increase in those belonging to the phylum Bacillota . The changes in gut flora are most profound in individuals who have diarrhoea-predominant IBS. Antibodies against common components (namely flagellin ) of
460-451: Is Bacillota. This includes Lactobacillus , which is found to have a decrease in people with IBS, and Streptococcus , which is shown to have an increase in abundance. Within this phylum, species in the class Clostridia are shown to have an increase, specifically Ruminococcus and Dorea . The family Lachnospiraceae presents an increase in IBS-D patients. The second most common phylum
506-532: Is Bacteroidota. In people with IBS, the Bacteroidota phylum has been shown to have an overall decrease, but an increase in the genus Bacteroides . IBS-D shows a decrease for the phylum Actinomycetota and an increase in Pseudomonadota, specifically in the family Enterobacteriaceae . Alterations of gut microbiota ( dysbiosis ) are associated with the intestinal manifestations of IBS, but also with
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#1732783854740552-568: Is a gastrointestinal agent used for the treatment of constipation-predominant IBS. The use of antispasmodic drugs (e.g., anticholinergics such as hyoscyamine or dicyclomine ) may help people who have cramps or diarrhea. A meta-analysis by the Cochrane Collaboration concludes that one out of seven people benefit from treatment with antispasmodics. Antispasmodics can be divided into two groups: neurotropics and musculotropics. Musculotropics, such as mebeverine , act directly at
598-954: Is also sometimes missed in people with diarrhea-predominant IBS. SeHCAT tests suggest around 30% of people with D-IBS have this condition, and most respond to bile acid sequestrants . Several medical conditions, or comorbidities , appear with greater frequency in people with IBS. IBS can be classified as diarrhea -predominant (IBS-D), constipation -predominant (IBS-C), with mixed/alternating stool pattern (IBS-M/IBS-A) or pain-predominant. In some individuals, IBS may have an acute onset and develop after an infectious illness characterized by two or more of: fever, vomiting, diarrhea, or positive stool culture . This post-infective syndrome has consequently been termed "post-infectious IBS" (IBS-PI). A number of treatments have been found to be effective, including fiber, talk therapy , antispasmodic and antidepressant medication, and peppermint oil. FODMAPs are short-chain carbohydrates that are poorly absorbed in
644-403: Is believed that psychological stress may trigger IBS in predisposed individuals. Given the high levels of anxiety experienced by people with IBS and the overlap with conditions such as fibromyalgia and chronic fatigue syndrome , a potential explanation for IBS involves a disruption of the stress system. The stress response in the body involves the hypothalamic–pituitary–adrenal axis (HPA) and
690-506: Is carried out to improve symptoms. This may include dietary changes, medication, probiotics , and counseling . Dietary measures include increasing soluble fiber intake, or a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs). The "low FODMAP" diet is meant for short to medium term use and is not intended as a life-long therapy. The medication loperamide may be used to help with diarrhea while laxatives may be used to help with constipation. There
736-414: Is highly restrictive in various groups of nutrients and can be impractical to follow in the long-term. More studies are needed to assess the true impact of this diet on health. In addition, the use of a low-FODMAP diet without verifying the diagnosis of IBS may result in misdiagnosis of other conditions such as celiac disease. Since the consumption of gluten is suppressed or reduced with a low-FODMAP diet,
782-407: Is not known but multiple factors have been proposed to lead to the condition. Theories include combinations of " gut–brain axis " problems, alterations in gut motility , visceral hypersensitivity, infections including small intestinal bacterial overgrowth , neurotransmitters , genetic factors, and food sensitivity . Onset may be triggered by a stressful life event, or an intestinal infection . In
828-465: Is recommended before a diagnosis of IBS is made. An upper endoscopy with small bowel biopsies is necessary to identify the presence of celiac disease. An ileocolonoscopy with biopsies is useful to exclude Crohn's disease and ulcerative colitis (Inflammatory bowel disease). Some people, managed for years for IBS, may have non-celiac gluten sensitivity (NCGS). Gastrointestinal symptoms of IBS are clinically indistinguishable from those of NCGS, but
874-407: Is recommended for those with fructose malabsorption. A low-FODMAP diet might help to improve short-term digestive symptoms in adults with irritable bowel syndrome, but its long-term follow-up can have negative effects because it causes a detrimental impact on the gut microbiota and metabolome . It should only be used for short periods of time and under the advice of a specialist. A low-FODMAP diet
920-399: Is strong clinical-trial evidence for the use of antidepressants , often in lower doses than that used for depression or anxiety, even in patients without comorbid mood disorder. Tricyclic antidepressants such as amitriptyline or nortriptyline and medications from the selective serotonin reuptake inhibitor (SSRI) group may improve overall symptoms and reduce pain. Patient education and
966-627: Is strongly associated with IBS regardless of whether IBS was initiated by an infection or not. A link between small intestinal bacterial overgrowth and tropical sprue has been proposed to be involved as a cause of post-infectious IBS. Small intestinal bacterial overgrowth (SIBO) occurs with greater frequency in people who have been diagnosed with IBS compared to healthy controls. SIBO is most common in diarrhea-predominant IBS but also occurs in constipation-predominant IBS more frequently than healthy controls. Symptoms of SIBO include bloating, abdominal pain, diarrhea or constipation among others. IBS may be
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#17327838547401012-551: Is twice as common in women as men and typically occurs before age 45. However, women in East Asia are not more likely than their male counterparts to have IBS, indicating much lower rates among East Asian women. Similarly, men from South America, South Asia and Africa are just as likely to have IBS as women in those regions, if not more so. The condition appears to become less common with age. IBS does not affect life expectancy or lead to other serious diseases. The first description of
1058-477: The Nav1.5 channel, in smooth muscle of the colon and pacemaker cells . Genetic, environmental, and psychological factors seem to be important in the development of IBS. The condition also has a genetic component even though there is a predominant influence of environmental factors. Dysregulated brain-gut axis, abnormal serotonin / 5-hydroxytryptamine (5-HT) metabolism, and high density of mucosal nerve fibers in
1104-436: The small intestine , as well as fructose and lactose , which are similarly poorly absorbed in those with intolerances to them. Reduction of fructose and fructan has been shown to reduce IBS symptoms in a dose-dependent manner in people with fructose malabsorption and IBS. FODMAPs are fermentable oligo- , di- , monosaccharides and polyols , which are poorly absorbed in the small intestine and subsequently fermented by
1150-424: The sympathetic nervous system , both of which have been shown to operate abnormally in people with IBS. Psychiatric illness or anxiety precedes IBS symptoms in two-thirds of people with IBS, and psychological traits predispose previously healthy people to developing IBS after gastroenteritis. Individuals with IBS also report high rates of sleep disturbances such as trouble falling asleep and frequent arousal throughout
1196-442: The bacteria in the distal small and proximal large intestine . This is a normal phenomenon, common to everyone. The resultant production of gas potentially results in bloating and flatulence. Although FODMAPs can produce certain digestive discomfort in some people, not only do they not cause intestinal inflammation, but they help avoid it, because they produce beneficial alterations in the intestinal flora that contribute to maintaining
1242-432: The commensal gut flora are a common occurrence in IBS affected individuals. Chronic low-grade inflammation commonly occurs in IBS affected individuals with abnormalities found including increased enterochromaffin cells , intraepithelial lymphocytes , and mast cells resulting in chronic immune-mediated inflammation of the gut mucosa. IBS has been reported in greater quantities in multigenerational families with IBS than in
1288-466: The condition is unclear. Vitamin D deficiency is more common in individuals affected by IBS. Vitamin D is involved in regulating triggers for IBS including the gut microbiome, inflammatory processes and immune responses, as well as psychosocial factors. SCN5A mutations are found in a small number of people who have IBS, particularly the constipation-predominant variant (IBS-C). The resulting defect leads to disruption in bowel function, by affecting
1334-408: The condition was in 1820, while the current term irritable bowel syndrome came into use in 1944. The primary symptoms of IBS are abdominal pain or discomfort in association with frequent diarrhea or constipation and a change in bowel habits. Symptoms usually are experienced as acute attacks that subside within one day, but recurrent attacks are likely. There may also be urgency for bowel movements,
1380-417: The form of a reduction in libido . While the causes of IBS are still unknown, it is believed that the entire gut–brain axis is affected. Recent findings suggest that an allergy triggered peripheral immune mechanism may underlie the symptoms associated with abdominal pain in patients with irritable bowel syndrome. IBS is more prevalent in obese patients. People who are younger than 50, women, and those with
1426-463: The good health of the colon. FODMAPs are not the cause of irritable bowel syndrome nor other functional gastrointestinal disorders , but rather a person develops symptoms when the underlying bowel response is exaggerated or abnormal. A low-FODMAP diet consists of restricting them from the diet. They are globally trimmed, rather than individually, which is more successful than for example restricting only fructose and fructans, which are also FODMAPs, as
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1472-511: The heterogeneity of types of fiber and doses used. Physical activity can have beneficial effects on irritable bowel syndrome. In light of this, the latest British Society of Gastroenterology guidelines on the management of IBS have stated that all patients with IBS should be advised to take regular exercise (strong recommendation, weak certainty evidence), whereas the American College of Gastroenterology guidelines have suggested with
1518-404: The illness. Antibiotic use also appears to increase the risk of developing IBS. Genetic defects in innate immunity and epithelial homeostasis increase the risk of developing both post-infectious as well as other forms of IBS. The role of the brain–gut axis in IBS has been suggested since the 1990s and childhood physical and psychological abuse is often associated with the development of IBS. It
1564-554: The improvement of the digestive symptoms with this diet may not be related to the withdrawal of the FODMAPs, but of gluten, indicating the presence of unrecognized celiac disease, avoiding its diagnosis and correct treatment, with the consequent risk of several serious health complications, including various types of cancer. Soluble fiber supplementation (e.g., psyllium/ispagula husk ) may be effective in improving symptoms. However soluble fiber does not appear to reduce pain. It acts as
1610-438: The intestines have been implicated in the mechanisms of IBS. A number of 5-HT receptor subtypes were involved in the IBS symptoms, including 5-HT 3 , 5-HT 4 , and 5-HT 7 receptors. High levels of 5-HT 7 receptor-expressing mucosal nerve fibers were observed in the colon of IBS patients. A role of 5-HT7 receptor in intestinal hyperalgesia was demonstrated in mouse models with visceral hypersensitivity , of which
1656-552: The latter case, it is called post-infectious irritable bowel syndrome . Diagnosis is based on symptoms in the absence of worrisome features and once other potential conditions have been ruled out. Worrisome or "alarm" features include onset at greater than 50 years of age, weight loss, blood in the stool , or a family history of inflammatory bowel disease . Other conditions that may present similarly include celiac disease , microscopic colitis , inflammatory bowel disease, bile acid malabsorption , and colon cancer . Treatment of IBS
1702-1099: The level of available medical resources. The Rome IV criteria for diagnosing IBS include recurrent abdominal pain, on average, at least one day/week in the last three months, associated with additional stool- or defecation-related criteria. The algorithm may include additional tests to guard against misdiagnosis of other diseases as IBS. Such "red flag" symptoms that may indicate other diseases as well include weight loss, gastrointestinal bleeding, anemia, or nocturnal symptoms. However, red flag conditions may not always contribute to accuracy in diagnosis; for instance, as many as 31% of people with IBS have blood in their stool, many possibly from hemorrhoidal bleeding. Investigations are performed to exclude other conditions: Colon cancer , inflammatory bowel disease , thyroid disorders ( hyperthyroidism or hypothyroidism ), and giardiasis can all feature abnormal defecation and abdominal pain. Less common causes of this symptom profile are carcinoid syndrome , microscopic colitis , bacterial overgrowth , and eosinophilic gastroenteritis ; IBS is, however,
1748-410: The night. Approximately 10 percent of IBS cases are triggered by an acute gastroenteritis infection. The CdtB toxin is produced by bacteria causing gastroenteritis and the host may develop an autoimmunity when host antibodies to CdtB cross-react with vinculin . Genetic defects relating to the innate immune system and epithelial barrier as well as high stress and anxiety levels appear to increase
1794-765: The presence of any of the following non-intestinal manifestations suggest a possible NCGS: headache or migraine , "foggy mind", chronic fatigue , fibromyalgia , joint and muscle pain, leg or arm numbness , tingling of the extremities, dermatitis ( eczema or skin rash ), atopic disorders , allergy to one or more inhalants, foods or metals (such as mites , graminaceae , parietaria , cat or dog hair/dander, shellfish , or nickel ), depression , anxiety , anemia , iron-deficiency anemia , folate deficiency , asthma , rhinitis , eating disorders , neuropsychiatric disorders (such as schizophrenia , autism , peripheral neuropathy , ataxia , attention deficit hyperactivity disorder ) or autoimmune diseases . An improvement with
1840-453: The psychiatric morbidity that coexists in up to 80% of people with IBS. Protozoal infections can cause symptoms that mirror specific IBS subtypes, e.g., infection by certain substypes of Blastocystis hominis ( blastocystosis ). Many people regard these organisms as incidental findings, and unrelated to symptoms of IBS. Blastocystis and Dientamoeba fragilis colonisation occurs more commonly in IBS affected individuals but their role in
1886-480: The regular population. It is believed that psychological stress can induce increased inflammation and thereby cause IBS to develop in predisposed individuals. No specific laboratory or imaging tests can diagnose irritable bowel syndrome. Diagnosis should be based on symptoms, the exclusion of worrisome features, and the performance of specific investigations to rule out organic diseases that may present similar symptoms. The recommendations for physicians are to minimize
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1932-449: The result of the immune system interacting abnormally with gut microbiota resulting in an abnormal cytokine signalling profile. Certain bacteria are found in lower or higher abundance when compared with healthy individuals. Generally Bacteroidota , Bacillota , and Pseudomonadota are increased and Actinomycetota , Bifidobacteria , and Lactobacillus are decreased. Within the human gut, there are common phyla found. The most common
1978-542: The risk of developing post-infectious IBS. Post-infectious IBS usually manifests itself as the diarrhea-predominant subtype. Evidence has demonstrated that the release of high levels of proinflammatory cytokines during acute enteric infection causes increased gut permeability leading to translocation of the commensal bacteria across the epithelial barrier; this in turn can result in significant damage to local tissues, which can develop into chronic gut abnormalities in sensitive individuals. However, increased gut permeability
2024-511: The small intestine. A 2018 systematic review found that although there is evidence of improved IBS symptoms with a low-FODMAP diet , the evidence is of very low quality. Symptoms most likely to improve on this type of diet include urgency, flatulence , bloating , abdominal pain, and altered stool output. One national guideline advises a low FODMAP diet for managing IBS when other dietary and lifestyle measures have been unsuccessful. The diet restricts various carbohydrates which are poorly absorbed in
2070-657: The smooth muscle of the gastrointestinal tract, relieving spasm without affecting normal gut motility. Since this action is not mediated by the autonomic nervous system, the usual anticholinergic side effects are absent. The antispasmodic otilonium may also be useful. Proton-pump inhibitors (PPIs) used to suppress stomach acid production may cause small intestinal bacterial overgrowth (SIBO) leading to IBS symptoms. Discontinuation of PPIs in selected individuals has been recommended as it may lead to an improvement or resolution of IBS symptoms. Functional gastrointestinal disorder Too Many Requests If you report this error to
2116-511: The use of medical investigations. The Rome criteria are typically used for diagnosis. They allow the diagnosis to be based only on symptoms, but no criteria based solely on symptoms is sufficiently accurate to diagnose IBS. Worrisome features include onset at greater than 50 years of age, weight loss, blood in the stool , iron-deficiency anemia , or a family history of colon cancer , celiac disease , or inflammatory bowel disease . The criteria for selecting tests and investigations also depends on
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