Irritable bowel syndrome is a common disease. It affects the large intestine which is part of colon. It causes gastrointestinal disturbance. It is a chronic disease which causes abdominal pain, bloating, and changes in the bowel patterns like constipation and diarrhea. It is a functional disease that has no structural abnormalities in the digestive tract which can imply symptoms.

The symptoms of IBS may vary between individuals and also include the abdominal cramping or pain, gas, bloating, constipation, diaarhea, or a combination of both. Some individuals may experience urgency in bowl movements or sense of incomplete evacuation. These symptoms may be unexpected and may vary on the severity over time.

IBS is a common disease which affect 10 to 15% of the global population. The greater rates are found in the developed countries. It is more common on female. The women to men ratio is 2:1. It is because of the psychosocial, hormonal, and genetic factors.

IBS may occur at any age, but mainly, it starts from early adulthood. The rate reduced at the age increases because of the inadequate reporting or changes in the diagnostic patterns. Many risk factors are associated with the development of IBS. Gastrointestinal infections. Psychological factors like anxiety, stress, depression, a family history of IBS, and specific dietary factors are the risk factors. In some cases, IBS may also be triggered by certain events like trauma, surgery, or life stressors.

Altered Gut Motility: The primary abnormality in IBS is the impaired normal gut motility. The muscles of GI tract contract in a coordinated manner to propel the food and waste by the digestive tract. Patients who have IBS have these contractions too week or too strong. This can lead to irregular bowel movements, bloating, or abdominal pain.

Visceral Hypersensitivity: Patients who have IBS may have elevated sensitivity to pain which is originated from the internal organs is called visceral hypersensitivity. The gut of patients who have IBS is more responsive to the normal stimuli like stool or gas passing via the intestines. The elevated sensitivity may lead to exaggerated pain signals which is transmitted to the brain. This may lead to abdominal pain or discomfort.

Intestinal Inflammation: IBS is not an inflammatory disease like inflammatory bowel disease (IBD). Some studies suggest that a low-grade inflammation can play role in the pathophysiology. Chronic inflammation may affect the normal functioning of the intestinal cells. This may alter the release of signaling molecules like cytokines. Cytokines may cause the symptoms of the IBS.

Gut-Brain Axis Dysfunction: Patients who have IBS may have a gut-brain signaling imbalance. This can lead to abnormal GI function and visceral hypersensitivity.

Microbiota Dysregulation: The gut microbiota which contains trillion of bacteria is essential to maintain gut health and normal GI function.

Abnormal gastrointestinal motility: IBS may lead to diarrhea or constipation because of the reduced or elevated motility of the intestines.

Visceral hypersensitivity: Patients who have IBS may have elevated sensitivity to pain in the GI tract. This may cause pain or discomfort at a low level of distention or stimulation in the intestine.

Intestinal inflammation: Patients who have IBS have low grade inflammation in the intestines. The origin and effects are not known.

Altered gut microbiota: Patients who have IBS have an imbalanced gut microbiota.

Genetic factors: Individuals who have a family history of IBS can be more likely to acquire the disease.

IBS generally has a good prognosis. The diagnosis is unlikely to change significantly during the follow up. Establishing an appropriate connection between physician and patient can help to decrease the dependency in ambulatory healthcare services.

Clinical history

Age Group: IBS may affect individuals at any age, from children to older adults. It is more diagnosed in the younger individuals. It affects the individuals between the ages from 20 years to 40 years.

Medical History: Healthcare provider will discuss the medical history which include the symptoms, their duration and a family history of the disease. They also may ask about the stress levels. Impact of the symptoms in the daily life, and dietary habits.

Abdominal Examination: The healthcare provider will examine the abdomen by gently palpitate the different areas to check for the bloating, abdominal masses, or tenderness. They may utilize the different degree of pressure to check if it increases the discomfort or pain.

Digital Rectal Examination (DRE): DRE is also performed in some cases to check the rectum and anal canal for any abnormalities like fissures or hemorrhoids.

Assessment of Organomegaly: The healthcare provider may palpate the other organs, like the spleen and liver, to check for any tenderness or enlargement.

Anxiety and depression: There is a strong link between IBS and psychological diseases like anxiety and depression. The exact link is complex and may vary among individuals. Emotional factors and stress may worsen the IBS symptoms. Patients who have IBS may have high level of depression and anxiety.

Fibromyalgia: Research has shown a significant connection between fibromyalgia and IBS. There is a high rate of IBS along with fibromyalgia and vice versa.

Chronic fatigue syndrome (CFS): CFS is also known as myalgic encephalomyelitis (ME). It is caused by high fatigue, cognitive difficulties, and other symptoms. There is a link between CFS and IBS. There is a high rate of IBS along with CFS and vice versa.

Gastroesophageal reflux disease (GERD): Some research has shown that there is an increased rate of GERD in patients who have IBS. There is a link between GERD and IBS.

Inflammatory bowel disease (IBD): IBD and IBS are two separate medical disease. They have certain symptoms which are overlap like abdominal pain and changes in the bowl movements. Some cases where patients may receive the diagnoses for both IBS and IBD like ulcerative colitis or Crohn’s disease. It is important to differ between these 2 disease to manage and treat the disease as they differ.

Abdominal pain or discomfort: This is a primary symptom of IBS. It is referred to as a cramping or aching pain in the lower abdomen.

Altered bowel habits: IBS may lead to changes in the bowel movements like constipation, diarrhea, or both. Some patients who experience the predominantly diarrhea (IBS-D) and other may experience the predominantly constipation (IBS-C). Some patients may alternate between constipation and diarrhea (IBS-M). 

Changes in stool appearance: IBS may lead to changes in the appearance of stool. It may range from watery to loosen stool to hard and lumpy stools. It depends on the subtype of IBS.

Bloating and distension: Patients who have IBS may experience bloating. It is feeling of swelling or fullness in the abdomen. 

Urgency and incomplete evacuation: Patients who have IBS may lead to a sense of urgency to have a bowel movement, and they feel like it is not empty even after going to the toilet.

Treatment paradigm

Lifestyle and dietary modifications: IBS symptoms can be improved by changing the lifestyle and diet. This includes eating a well-balanced diet, identify the trigger foods, eating smaller and frequent foods, stay hydrates, and manage the stress.

Medications: Medications can be given to manage specific symptoms of IBS. These include:

Fiber supplements: Supplements like psyllium may help to regulate bowel movements and relieve constipation.

Antispasmodics: These medications may help to reduce the cramping and abdominal pain by relaxing the muscles of the intestines.

Antidiarrheal medications: These medications may help to control diarrhea symptoms.

Low-dose antidepressants: Certain antidepressants, like tricyclic antidepressants, may help to reduce abdominal pain and regulate bowel movements in lower doses.

Probiotics: Probiotics helps to reduce the symptoms in some individuals with IBS.

Psychological therapies: There is a link between IBS symptoms and psychological factors and therapies. It can be beneficial as a psychological aspect. These include mindfulness-based stress reduction and cognitive behavioral therapy (CBT)

Nutrition

Increase fiber intake: A type of a soluble fiber is psyllium husk. It has a potential to regulate the bowel movements and relieve the constipation. It absorbs the water in the intestine and enhance the stool size and regularity. Metamucil and FiberCon are the supplement of psyllium husk which are available in the market.

Stay hydrated: Stay hydrated to regulate the bowel movements and prevent constipation. It is suggested to drink minimum 8 glasses of water per day. It is suggested to take moderate intake of alcohol and caffeine beverages to avoid the constipation.

Limit trigger foods: To manage the IBS symptoms, it is important to adjust the diet. It is important to identify and trigger the food which can elevate the symptoms. Spicy foods, fatty foods, alcohol, caffeine, artificial sweeteners. Carbonated beverages are examples. It is necessary to focus on a well-balanced diet which contain high fiber like fruits, vegetables, whole gains, and lean proteins.

Low FODMAPs diet: The low FODMAPs diet is widely used as a dietary supplement to manage the symptoms of IBS. FODMAP are a group of carbohydrates, sugar alcohols which may be not able to absorb by the small intestine. This malabsorption may lead to increased levels of water content and gas production within the GI tract. It leads to the symptoms of IBS.

Lactose avoidance: Patients who are lactose intolerance is suggested to exclude lactose from the diet to reduce the symptoms of IBS.

Gluten avoidance: Celiac disease and gluten sensitivity are two different diseases from IBS. Some patients who have IBS may have gluten intolerance or non-celiac gluten sensitivity. It is suggested to avoid gluten containing food to reduce the symptoms in these cases.

Exclusion of gas-producing foods:

Beans and legumes: Lentils, chickpeas, beans and other legumes contain a complex of carbohydrates. It is difficult to digest which lead to gas production.

Cruciferous vegetables: Vegetables like cabbage, broccoli, cauliflower, and Brussels sprouts contain a carbohydrate called raffinose. It is a type of fermentable carbohydrate. It can ferment in the gut and lead to gas.

Onions and garlic: Garlic and onions contain fructans. It is a type of a fermentable carbohydrate. It can lead to gas and bloating.

Certain fruits: Apples, pears, and stone fruits like peaches, plums, and cherries contain polyols. It is a fermentable sugars. It can lead to gas and bloating.

Probiotics: Probiotics are live microorganism. When probiotics are ingested in appropriate amount, it can be advantageous. The beneficial bacteria which present in the specific foods like yogurt can regulate the gut microbiota and promote well digestive system.

Infectious Disease

Low-impact aerobic exercises: Keep your self-engaged in the low impact activities like swimming, walking, or cycling may help to stimulate the bowel movements and reduce the constipation.

Yoga: Yoga poses like gentle twists and forward bends may also help to reduce digestive discomfort. Always look for beginner or gentle yoga classes that focus on flexibility and relaxation.

Managing stress: Engage yourself into stress reducing activities like mediation, exercise, and deep breathing exercises.

Infectious Disease

Cognitive-behavioral therapy (CBT): CBT may help to manage the anxiety, stress, and negative thoughts which are associated with IBS. This can reduce the symptoms.

Mindfulness-based stress reduction: Practices like mindful ness meditation and yoga may be helpful to manage stress and improve the overall well-being.

Gastroenterology

Osmotic laxatives like polyethylene glycol (PEG), lactulose, or magnesium hydroxide are used to treat constipation. Constipation is a symptom of IBS, the main cause of constipation in IBS is multifactorial and linked to abnormal gut motility, changes in gut microbiota, and visceral hypersensitivity. The use of osmotic laxatives in IBS who have constipation-predominant IBS (IBS-C) and failed to respond to the lifestyle changes and dietary changes, or other therapies are beneficial for those.

Gastroenterology

Lubiprostone is primarily prescribed to treat IBS-C in adults. It is prescribed to those who are not getting any benefits from the lifestyle and dietary changes with the symptoms like abdominal pain, bloating, and constipation.

The recommended dose of Lubiprostone for IBS-C is 8 mcg twice a day with water and food. The dosage may be adjusted by a healthcare provider as per the respone and tolerability of patient.

Gastroenterology

Linaclotide: Linaclotide is a guanylate cyclase agonist. It has been investigating for IBS. Linaclotide increases the production of cyclic guanosine monophosphate (cGMP). It is a signalling molecule which help to regulate the fluid secretion and motility in the intestine. Linaclotide can reduce the symptoms of IBS, specifically IBS-C by elevating the level of cCMP.

Plecanatide: Plecanatide increases the secretion of fluid into the intestine and accelerate the bowel movement. It helps to relive the constipation linked with IBS-C. It also activates the guanylate cyclase-C receptor in the intestine and lead to increased fluid secretion and regulate bowel movement.

Gastroenterology

Tenapanor: Tenapanor is a NHE3 inhibitors. It reduces the absorption of sodium in the intestine. It leads to elevated water content in the stool and regulated bowel movement. It helps to relieve from the constipation.

Gastroenterology

Tegaserod: Tegaserod is a pharmaceutical intervention to reduce the symptoms linked with the IBS-C. It stimulates the movement in the intestine and helps to reduce the symptoms like constipation and abdominal pain.

Gastroenterology

Loperamide: Loperamide is a medication which is used to treat the acute or chronic diarrhea. It slows down the bowel movement tin the intestines and allow to increase the water absorption and firm up the stool.

Gastroenterology

Cholestyramine and colesevelam:

Bile acid sequestrants bind to the bile acids in the intestine and prevent the reabsorption. It is used to lower the cholesterol level. Bile acids play an important role in the intestine function and can interact with the receptors in the gut which can influence the bowel symptoms.

Gastroenterology

5-HT3 receptor antagonists like ondansetron and alosetron are known for anti-nausea and anti-vomiting effects. It is also useful to manage the IBS symptoms. It blocks the actions of the serotonin at the 5-HT3 receptors in the GI tract. It reduces the GI motility and visceral hypersensitivity which can help to reduce the symptoms like abdominal pain, bloating, and diarrhea. They modulate the abnormal gut activity.

Gastroenterology

Eluxadoline is a selective agonist of the mu-opioid receptor and delta-opioid receptor. It helps to regulate GI motility and reduce abdominal pain linked with IBS-D.

Abdominal pain and bloating 

Gastroenterology

Dicyclomine is an anticholinergics medication. It helps to relaxe the smooth muscles in the GI tract. It helps to reduce the intestinal spasm and cramping. Dicyclomine is taken orally in a tablet form before meals

Hyoscyamine is another anticholinergic medication. It works like dicyclomine. It relieves the GI spasms, abdominal pain, and cramping linked with IBS. Hyoscyamine is available in various forms like tablets, capsules, and sublingual (under the tongue) preparations.

Gastroenterology

Tricyclic antidepressants (TCAs): Medications like amitriptyline and nortriptyline help to relieve the pain and reduce the bowel symptoms linked with IBS. TCAs may affect the neurotransmitters in the gut, reduce the pain, and improve the gut motility.

Gastroenterology

Antibiotics like rifaximin may be prescribed to target the overgrowth of the bacterial to reduce the symptoms. Rifaximin is a non-absorbable antibiotic. It locally acts in the gut and minimize the side effects.

Gastroenterology

Education and Lifestyle Modifications: Patients are educated about the IBS, symptoms, triggers and treatments after the diagnosis. Lifestyle modifications play an important role to manage the IBS symptoms. It includes dietary changes, stress management techniques, regular exercise, and improve sleep habits.

Dietary Modifications: Dietary modifications are important to manage IBS. Patients are advised to follow the specific diets like the low-FODMAP diet. Other dietary modifications like to involve fiber intake or to avoid certain food like spicy or fatty foods.

Medications: Healthcare providers may suggest medication to manage IBS in some cases. The medication choice is dependent on the predominant symptom and include medications like antispasmodics to reduce muscle spasms, laxatives for constipation-predominant IBS, or medications to reduce the specific symptoms like pain or diarrhea. Probiotics are also used to promote the healthy gut microbiota.

Psychological Support: Psychological factors like stress, anxiety, and depression can increase IBS symptoms. Patients who get the benefit of cognitive-behavioral therapy (CBT) can manage stress and improve the coping strategy. Relaxation techniques, mindfulness, and hypnotherapy are used.