Irritable Bowel Syndrome Management

Irritable bowel syndrome (IBS), referred to previously as spastic or nervous colon, and spastic bowel, is a functional gastrointestinal disorder characterized by a group of symptoms accompanied together that include abdominal pain and changes in the consistency of bowel movements. These symptoms occur over a long time, often years. It has been classified into four main types depending on whether diarrhea is common, constipation is common, both are common (mixed/alternating), or neither occurs very often. IBS negatively affects the quality of life and may result in missed school or work. There is no known cure for IBS. About 10–15% of people in the developed world are believed to be affected by IBS.

Who is more likely to develop IBS?

Women are up to two times more likely than men to develop IBS. People younger than age 50 are more likely to develop IBS than people older than age 50.

Factors that can increase the chance of having IBS include:

• Having a family member with IBS.
• A history of stressful or difficult life events, such as abuse, in childhood.
• Having a severe infection in your digestive tract.

Irritable bowel syndrome Classification

IBS can be classified as:

• Diarrhea-predominant (IBS-D),
• Constipation-predominant (IBS-C),
• 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: fever, vomiting, diarrhea, or positive stool culture. This post-infective syndrome has consequently been termed “postinfectious IBS” (IBS-PI).

Irritable bowel syndrome Symptoms

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, a feeling of incomplete evacuation, 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 and anxiety. About a third of adults who have IBS also report sexual dysfunction, typically in the form of a reduction in libido.

Irritable bowel syndrome Cause

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.

Risk factors

The risk of developing IBS increases six-fold after an acute gastrointestinal infection. Postinfection, further risk factors are:

• Young age,
• Prolonged fever,
• Anxiety, and
• Depression.

Psychological factors, such as depression or anxiety, have not been shown to cause or influence the onset of IBS but may play a role in the persistence and perceived severity of symptoms. Nevertheless, they may worsen IBS symptoms and quality of life. Antibiotic use also appears to increase the risk of developing IBS. 

Stress

Publications suggest the role of the brain-gut axis appeared in the 1990s and childhood physical and psychological abuse is often associated with the development of IBS. It 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. 

Post-infectious

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 autoimmunity when host antibodies to CdtB cross-react with vinculin.

However, increased gut permeability 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.

Bacteria

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-predominate 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 the result of the IMMUNE SYSTEM interacting abnormally with gut microbiota resulting in an abnormal cytokine signaling profile.

Fungus

There is growing evidence that alterations of gut microbiota (dysbiosis) are associated with the intestinal manifestations of IBS, but also with the psychiatric morbidity that coexists in up to 80% of people with IBS.

The role of the gut mycobiota, and especially of the abnormal proliferation of the yeast Candida albicans in some people with IBS, was under investigation as of 2005.

Protozoa

Protozoal infections can cause symptoms that mirror specific IBS subtypes, e.g. infection by certain subtypes of Blastocystis hominis (blastocystosis).

As of 2017, evidence indicates that blastocystis colonization occurs more commonly in IBS-affected individuals and is a possible risk factor for developing IBS. Dientamoeba fragilis has also been considered a possible organism to study, though it is also found in people without IBS.

Vitamin D

This deficiency is more common in individuals affected by irritable bowel syndrome. Vitamin D is involved in regulating triggers for IBS including the gut microbiome, inflammatory processes, and immune responses, as well as psychosocial factors.

Genetics

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.

Irritable bowel syndrome Diagnosis

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.

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 depend on the level of available medical resources.

Rome criteria

The Rome IV criteria include recurrent abdominal pain, on average, at least one day/week in the last three months, associated with two or more of the following further criteria:

• Related to defecation.
• Associated with a change in the frequency of stool.
• Associated with a change in form (appearance) of stool.

Physicians may choose to use one of these guidelines or may simply choose to rely on their own anecdotal experience with past patients. The algorithm may include additional tests to guard against misdiagnosis of other diseases such as IBS. Such “red flag” symptoms may include weight loss, gastrointestinal bleeding, anemia, or nocturnal symptoms.

Irritable bowel syndrome Differential diagnosis

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, 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.

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 the presence of any of the following non-intestinal manifestations suggests 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, 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 a gluten-free diet of immune-mediated symptoms, including autoimmune diseases, once having reasonably ruled out coeliac disease and wheat allergy is another way to realize a differential diagnosis.

Investigations

Investigations are performed to exclude other conditions:

• Stool microscopy and culture (to exclude infectious conditions).
• Blood tests: Full blood examination, liver function tests, erythrocyte sedimentation rate, and serological testing for coeliac disease.
• Abdominal ultrasound (to exclude gallstones and other biliary tract diseases).
• Endoscopy and biopsies (to exclude peptic ulcer disease, coeliac disease, inflammatory bowel disease, and malignancies).
• Hydrogen breath testing (to exclude fructose and lactose malabsorption).

Irritable bowel syndrome Misdiagnosis

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, and parasites (non-protozoal). The American College of Gastroenterology recommends all people with symptoms of IBS be tested for coeliac disease.

Bile acid malabsorption 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.

Irritable bowel syndrome Management

A number of treatments have been found to be effective, including fiber, talk therapy, antispasmodic and antidepressant medication, and peppermint oil.

Diet

Irritable bowel syndrome is a medical condition characterized by abdominal pain and changes in bowel movement that, unlike inflammatory bowel disease (IBD), does not involve intestinal damage. In addition to IBS-C and IBS-D, there is also mixed-type IBS (IBS-M) in which diarrhea and constipation alternate.

In the same way that the cause of IBS is unclear, there has been limited clinical research to evaluate the effectiveness of various diets in treating the disease. What scientists do know is that specific foods and dietary practices are closely linked to the onset of IBS symptoms.

FODMAP

FODMAPs are short-chain carbohydrates that are poorly absorbed in 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 that are most likely to improve include urgency, flatulence, bloating, abdominal pain, and altered stool output. FODMAPs are not the cause of irritable bowel syndrome or other functional gastrointestinal disorders, but rather a person develops symptoms when the underlying bowel response is exaggerated or abnormal.

In addition, the use of a low-FODMAP diet without verifying the diagnosis of IBS may result in the misdiagnosis of other conditions such as celiac disease. 

Fiber

Some evidence suggests soluble fiber supplementation (e.g. psyllium/ispagula husk) is effective. It acts as 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.

One meta-analysis found only soluble fiber improved global symptoms of irritable bowel, but neither type of fiber reduced pain. An updated meta-analysis by the same authors also found soluble fiber reduced symptoms, while insoluble fiber worsened symptoms in some cases. Positive studies have used 10–30 grams per day of ispaghula (psyllium). One study specifically examined the effect of dose and found that 20 g of ispaghula (psyllium) was better than 10 g and equivalent to 30 g per day.

Physical Activity

Recent studies have demonstrated the potential beneficial effects of Physical activity on irritable bowel syndrome. Some randomized controlled trials (RCTs) have demonstrated a beneficial effect of physical activity on IBS symptoms. Three RCTs showed a significant improvement in the Irritable Bowel Syndrome – Severity Scoring System, while 1 RCT showed a significant improvement only in symptoms of constipation.

In light of this, the latest British Society of Gastroenterology guidelines on the management of IBS has 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 a lower certainty of evidence. 

Medication for 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.

Serotonergic agents

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 the food and drug administration and are now prescribed under emergency investigational drug protocol. Other 5-HT receptor subtypes, such as the 5-HT7 receptor, have yet to be developed.

Laxatives

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 is a gastrointestinal agent used for the treatment of constipation-predominant IBS.

Antispasmodics

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 if seven people are treated with antispasmodics, one of them will benefit. 

Discontinuation of proton pump inhibitors

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.

Antidepressants

Evidence is conflicting about the benefit of antidepressants in IBS. Some meta-analyses have found a benefit, while others have not. There is good evidence that low doses of tricyclic antidepressants (TCAs) can be effective for IBS. With TCAs, about one in three people improve.

Other agents

Magnesium aluminum silicates and alverine citrate drugs can be effective for IBS.

Rifaximin may be useful as a treatment for IBS symptoms, including abdominal bloating and flatulence, although relief of abdominal distension is delayed. It is beneficial where small intestinal bacterial overgrowth is involved.

In individuals with IBS and low levels of vitamin D supplementation is recommended. Some evidence suggests that vitamin D supplementation may improve symptoms of IBS, but further research is needed before it can be recommended as a specific treatment for IBS.

Psychological therapies

There is low quality evidence from studies with poor methodological quality that psychological therapies can be effective in the treatment of IBS; however, there are no significant adverse effects from psychological therapies for IBS. 

Reducing stress may reduce the frequency and severity of IBS symptoms. Techniques that may be helpful include:

• Relaxation techniques such as meditation.
• Physical activities such as yoga or tai chi.
• Regular exercise such as swimming, walking, or running.

Vagus nerve stimulation

Vagus nerve stimulation has anti-inflammatory effects and its potential for the treatment of IBS is actively researched.

Alternative medicine

A meta-analysis found no benefits of acupuncture relative to a placebo for IBS symptom severity or IBS-related quality of life.

Probiotics

Probiotics can be beneficial in the treatment of IBS; taking 10 billion to 100 billion beneficial bacteria per day is recommended for beneficial results. However, further research is needed on individual strains of beneficial bacteria for more refined recommendations.

Probiotics have positive effects such as enhancing the intestinal mucosal barrier, providing a physical barrier, bacteriocin production (resulting in reduced numbers of pathogenic and gas-producing bacteria), reducing intestinal permeability and bacterial translocation, and regulating the immune system both locally and systemically among other beneficial effects. 

Herbal remedies

Peppermint oil appears useful. In a meta-analysis, it was found to be superior to a placebo for the improvement of IBS symptoms, at least in the short term. An earlier meta-analysis suggested the results of peppermint oil were tentative as the number of people studied was small and the blinding of those receiving treatment was unclear.

Safety during pregnancy has not been established, however, and caution is required not to chew or break the enteric coating; otherwise, gastroesophageal reflux may occur as a result of lower esophageal sphincter relaxation. Occasionally, nausea and perianal burning occur as side effects. Iberogast, a multi-herbal extract, was found superior in efficacy to a placebo. 

Siddha remedies for Irritable bowel syndrome 

Reference: https://en.wikipedia.org/wiki/Irritable_bowel_syndrome