Irritable bowel syndrome (IBS) is a functional gastrointestinal (GI) disorder, which means that the symptoms arise from changes in how the GI tract operates. Individuals with a functional GI disorder experience frequent symptoms, but their GI tract remains undamaged. IBS consists of a collection of symptoms that occur together, rather than being classified as a disease. Historically, IBS was referred to as colitis, mucous colitis, spastic colon, nervous colon, and spastic bowel. The name was updated to better reflect the understanding that the disorder has both physical and psychological components and is not merely a figment of a person’s imagination.

A diagnosis of IBS is made when a person experiences abdominal pain or discomfort at least three times a month over the past three months, without any other disease or injury that could account for the pain. The discomfort associated with IBS may coincide with changes in stool frequency or consistency, or it may be alleviated by a bowel movement.

IBS is typically categorized into four subtypes based on an individual’s usual stool consistency. These subtypes are significant because they influence the types of treatments that are most likely to alleviate the person’s symptoms.

What are the different types of IBS?

The four subtypes of IBS are:

1. IBS with constipation (IBS-C)

• – hard or lumpy stools at least 25% of the time
  – loose or watery stools less than 25% of the time
• Primary symptom: Constipation.
• Features:
  • Hard, lumpy stools.
  • Fewer bowel movements.
  • Abdominal pain and bloating.

2. IBS with diarrhea (IBS-D)

• – loose or watery stools at least 25% of the time
  – hard or lumpy stools less than 25% of the time
• Primary symptom: Diarrhea.
• Features:
  • Frequent, loose, or watery stools.
  • Urgency to use the bathroom.
  • Abdominal cramping.

3. Mixed IBS (IBS-M)

• – hard or lumpy stools at least 25% of the time
  – loose or watery stools at least 25% of the time
• Alternates between constipation and diarrhea.
• Features:
  • Unpredictable bowel habits.
  • Mixed stool consistency.
  • Associated abdominal discomfort.

4. Unsubtyped IBS (IBS-U)

• – hard or lumpy stools less than 25% of the time
  – loose or watery stools less than 25% of the time.
• Symptoms do not fit neatly into the other categories.
• Features:
  • Less defined pattern of bowel movements.
  • Abdominal pain may still be present.

What Is GI ( Gestor Intestinal )tract ?

The gastrointestinal (GI) tract is a complex system of hollow organs that forms a long, twisting tube extending from the mouth to the anus, which is the exit point for stool. Digestion occurs through the coordinated movement of muscles in the GI tract, along with the secretion of hormones and enzymes. The GI tract includes several key organs: the mouth, esophagus, stomach, small intestine, and large intestine, which encompasses the appendix, cecum, colon, rectum, and anus. The intestines are often referred to as the bowel. The final section of the GI tract, known as the lower GI tract, comprises the large intestine and anus.

The large intestine plays a crucial role in absorbing water and any leftover nutrients from the partially digested food that comes from the small intestine. It then transforms this waste from a liquid state into solid stool. Stool travels from the colon to the rectum, which is situated between the sigmoid colon and the anus. The rectum serves as a storage area for stool until a bowel movement occurs, at which point the stool is expelled from the rectum through the anus.

How common is IBS and who is affected?

Research suggests that IBS impacts between 3 to 20 percent of adults, with most studies indicating a prevalence of 10 to 15 percent. However, only about 5 to 7 percent of adults have actually received a diagnosis for the condition. IBS is more common in women, affecting roughly twice as many as men, and is typically seen in individuals under the age of 45.

What are the causes of IBS?

The exact causes of IBS remain unclear. Researchers suggest that a mix of physical and mental health issues may contribute to the development of IBS.

Brain-Gut Signal Problems

Signals between the brain and the nerves in the small and large intestines, collectively known as the gut, play a crucial role in regulating intestinal function. Disruptions in these brain-gut signals can lead to IBS symptoms, including alterations in bowel habits and discomfort.

GI Motor Problems

Individuals with IBS may experience abnormal motility, or movement, in their colon. Slow motility can result in constipation, while rapid motility can cause diarrhea. Additionally, spasms—sudden, intense muscle contractions that occur intermittently—can lead to abdominal pain. Some individuals with IBS may also experience hyperreactivity, which is a significant increase in bowel contractions triggered by stress or eating.

Hypersensitivity

Individuals with IBS tend to have a lower pain threshold when it comes to bowel stretching due to gas or stool, especially in comparison to those without IBS. It appears that the brain may interpret pain signals from the bowel differently in those who have IBS.

Mental Health Problems

Psychological issues such as panic disorder, anxiety, depression, and post-traumatic stress disorder are frequently observed in individuals with IBS. The relationship between these mental health conditions and the onset of IBS remains unclear. Gastrointestinal disorders, including IBS, are often seen in individuals who have experienced past physical or sexual abuse. Researchers suggest that those who have been abused may manifest psychological stress through physical symptoms.

Bacterial Gastroenteritis

Some individuals who experience bacterial gastroenteritis—an infection or irritation of the stomach and intestines caused by bacteria—go on to develop IBS. The reasons why gastroenteritis results in IBS for some people but not for others are still unknown, although abnormalities in the GI tract lining and psychological issues may play a role.

Small Intestinal Bacterial Overgrowth

Typically, there are only a few bacteria present in the small intestine. Small intestinal bacterial overgrowth occurs when there is an increase in the number or a change in the type of bacteria found in this part of the digestive system. These bacteria can produce excess gas and may lead to diarrhea and weight loss. Some researchers suggest that small intestinal bacterial overgrowth could contribute to IBS, and certain studies have indicated that antibiotics may be effective in treating IBS. However, further research is necessary to establish a definitive connection between small intestinal bacterial overgrowth and IBS.

Body Chemicals

Individuals with IBS often have altered levels of neurotransmitters—chemicals that transmit nerve signals—and gastrointestinal hormones, although the exact role these chemicals play in the development of IBS remains unclear. Younger women with IBS frequently experience more symptoms during their menstrual cycles, while postmenopausal women tend to have fewer symptoms compared to those who are still menstruating. These observations imply that reproductive hormones may exacerbate IBS symptoms.

Genetics

It is still uncertain whether IBS has a genetic component, meaning it may run in families. Research has indicated that IBS is more prevalent among individuals who have family members with a history of gastrointestinal issues. However, the underlying cause could also be environmental or due to an increased awareness of gastrointestinal symptoms.

Food Sensitivity

Many individuals with IBS report that their symptoms are triggered by foods high in carbohydrates, as well as spicy or fatty foods, coffee, and alcohol. However, those with food sensitivities generally do not exhibit clinical signs of food allergies. Researchers have suggested that these symptoms may stem from poor absorption of sugars or bile acids, which are essential for breaking down fats and eliminating waste from the body.

What are the symptoms of IBS?

The most common symptoms of IBS include abdominal pain or discomfort, often described as cramping, along with changes in bowel habits. For a diagnosis of IBS, the pain or discomfort must be linked to at least two of the following three symptoms:

• bowel movements that happen more or less frequently than usual
• stool that is either less solid and more watery, or harder and lumpier than normal
• bowel movements that relieve the discomfort
  Additional symptoms of IBS may consist of:
• diarrhea—experiencing loose, watery stools three or more times a day, along with a strong urge to have a bowel movement.
• constipation—having fewer than three bowel movements per week. During these movements, stools can be hard, dry, and small, making them difficult to pass. Some individuals may find this painful and often need to strain.
• a sensation that a bowel movement is incomplete.
• passing mucus—a clear fluid produced by the intestines that helps coat and protect the tissues in the GI tract.
• abdominal bloating.

Symptoms often arise after eating a meal. To qualify as IBS, symptoms must occur at least three times a month.

How is IBS diagnosed?

To diagnose IBS, a healthcare provider will perform a physical exam and gather a comprehensive medical history. This history will involve questions about symptoms, any family history of gastrointestinal disorders, recent infections, medications taken, and any stressful events that may have triggered the symptoms. For an IBS diagnosis, it is necessary that symptoms began at least 6 months ago and occurred at least three times a month over the last 3 months. Typically, further testing isn’t required, but the healthcare provider might conduct a blood test to rule out other issues. Additional tests may be necessary depending on the results of the blood screening and for individuals who exhibit symptoms such as:

• fever
• rectal bleeding
• weight loss
• anemia—an insufficient number of red blood cells, which can hinder the body’s oxygen supply
• family history of colon cancer
• family history of irritable bowel disease—chronic conditions that lead to irritation and ulcers in the gastrointestinal tract
• family history of celiac disease—an abnormal immune response to gluten, a protein in wheat, rye, and barley, which damages the small intestine lining and hinders nutrient absorption

Further diagnostic tests might include a stool test, lower GI series, and flexible sigmoidoscopy or colonoscopy. A colonoscopy may also be advised for individuals over 50 to check for colon cancer.

Test and radiology perform for diagnosis of IBS.

Stool Routine Examination (Stool R/E)

A stool test involves analyzing a sample of stool. The healthcare provider will provide a container for collecting and storing the stool. Once collected, the sample is returned to the healthcare provider or a commercial facility and sent to a lab for analysis. Additionally, the healthcare provider may perform a rectal exam, often during a physical examination, to check for blood in the stool. Stool tests can detect the presence of parasites or blood.

X Rays (lower GI series)

A lower GI series is an X-ray used to examine the large intestine. This test is conducted at a hospital or outpatient center by an X-ray technician, and a radiologist—a doctor who specializes in medical imaging—interprets the images. Anesthesia is not required. Prior to the test, the healthcare provider may provide written instructions for bowel preparation to be followed at home. The individual may be asked to adhere to a clear liquid diet for 1 to 3 days leading up to the procedure. A laxative or an enema might be used beforehand. A laxative is a medication that helps to soften stool and increase bowel movements, while an enema involves introducing water or laxative into the anus using a special squirt bottle.

During the test, the individual will lie on a table while the radiologist carefully inserts a flexible tube into the anus. This allows the large intestine to be filled with barium, which helps to highlight any underlying issues more clearly on x-rays.

For a few days following the procedure, the presence of barium in the large intestine may result in stools appearing white or light-colored. Additionally, enemas and frequent bowel movements could lead to some anal soreness. A healthcare provider will give detailed instructions regarding eating and drinking after the test.

Flexible sigmoidoscopy and colonoscopy

Flexible sigmoidoscopy and colonoscopy are similar procedures, but colonoscopy allows for examination of the rectum and the entire colon, whereas flexible sigmoidoscopy focuses only on the rectum and lower colon. These tests are typically conducted in a hospital or outpatient center by a gastroenterologist, a specialist in digestive diseases. Prior to either procedure, patients receive written bowel preparation instructions to follow at home. They may be required to adhere to a clear liquid diet for 1 to 3 days leading up to the test. The night before, patients might need to take a laxative or use one or more enemas, with additional enemas possibly needed about 2 hours before a flexible sigmoidoscopy.

During a colonoscopy, light anesthesia and possibly pain medication are often administered to help patients relax. For both tests, the patient lies on a table while the gastroenterologist inserts a flexible tube into the anus. A small camera attached to the tube transmits video images of the intestinal lining to a computer screen, allowing for the detection of issues in the lower GI tract.

Biopsy

The gastroenterologist may also perform a biopsy, which involves taking a small sample of the intestinal lining for microscopic examination. Patients typically do not feel the biopsy. A pathologist, who specializes in disease diagnosis, analyzes the tissue in a laboratory.

After either test, some cramping or bloating may occur during the first hour. Patients are advised not to drive for 24 hours following a colonoscopy to ensure the sedative has worn off. It’s important to arrange for a ride home before the appointment, and most individuals can expect to fully recover by the next day.

IBS ( Irritable Bowel Syndrome). pdf

How is IBS treated?

While there is no cure for IBS, its symptoms can be managed through a combination of:

• Changes in eating habits, diet, and nutrition
• Medications
• Probiotics
• Therapies for mental health issues

Eating, Diet, and Nutrition

Large meals can lead to cramping and diarrhea, so opting for smaller, more frequent meals or reducing portion sizes may alleviate IBS symptoms. Meals that are low in fat and rich in carbohydrates, such as pasta, rice, whole-grain breads and cereals, fruits, and vegetables, can be beneficial.

Certain foods and beverages may trigger IBS symptoms in some individuals, including:

• High-fat foods
• Certain dairy products
• Alcoholic or caffeinated drinks
• Beverages containing large amounts of artificial sweeteners
• Beans, cabbage, and other gas-producing foods

Those with IBS might consider limiting or avoiding these items. Keeping a food diary can be an effective way to identify which foods provoke symptoms, allowing for their exclusion or reduction in the diet.

Dietary fiber can help improve constipation symptoms in people with IBS, although it may not alleviate pain. Fiber helps soften stool, facilitating smoother movement through the colon. Adults are generally recommended to consume between 21 to 38 grams of fiber daily. However, fiber can also cause gas and trigger symptoms in some individuals with IBS. Gradually increasing fiber intake by 2 to 3 grams per day may help minimize the risk of gas and bloating.

Medication

A healthcare provider will choose medications based on an individual’s symptoms.

• Fiber supplements
  • Might be suggested to alleviate constipation when increasing dietary fiber intake doesn’t work.
• Laxatives
  • can assist with constipation. They function in various ways, and a healthcare provider can offer guidance on which type is most suitable for each person. For more information, visit Constipation at www.digestive.niddk.nih.gov.
• Loperamide
  • is an antidiarrheal medication that has been shown to decrease diarrhea in individuals with IBS, although it does not alleviate pain, bloating, or other symptoms. It works by slowing down stool movement through the colon, which reduces stool frequency and improves consistency.
• Antispasmodics
  • like hyoscine, cimetropium, and pinaverium, are effective in managing colon muscle spasms and easing abdominal pain.
• Antidepressants
  • including low doses of tricyclic antidepressants (TCAs) and selective serotonin reuptake inhibitors (SSRIs), can help relieve IBS symptoms, such as abdominal pain. Theoretically, TCAs may be more beneficial for those with IBS-D, while SSRIs might be better for those with IBS-C due to their impact on colon transit, although this theory hasn’t been validated in clinical studies. TCAs help individuals with IBS by decreasing pain sensitivity in the GI tract and normalizing GI motility and secretion.
• Lubiprostone (Amitiza)
  • is often prescribed for individuals with IBS-C. This medication has been shown to alleviate symptoms such as abdominal pain or discomfort, improve stool consistency, reduce straining, and lessen the severity of constipation.
• Linaclotide (Linzess)
  • is another option for those with IBS-C, as it has been effective in relieving abdominal pain and increasing bowel movement frequency.

The antibiotic rifaximin may help reduce abdominal bloating by addressing small intestinal bacterial overgrowth; however, the use of antibiotics for treating IBS remains a topic of debate among scientists, indicating that further research is necessary.

Probiotics

Probiotics are live microorganisms, typically bacteria, that resemble those found naturally in the gastrointestinal tract. Research suggests that when consumed in sufficient quantities, probiotics—particularly Bifidobacteria and certain combinations—can improve IBS symptoms. Nonetheless, additional studies are warranted. Probiotics are available in dietary supplements like capsules, tablets, and powders, as well as in some foods, such as yogurt.

It’s advisable for individuals to consult with a healthcare provider to determine the appropriate type and dosage of probiotics for managing IBS symptoms. To ensure safe and coordinated care, patients should discuss any complementary and alternative medical practices, including dietary supplements and probiotics, with their healthcare provider. For more information, visit www.nccam.nih.gov/health/probiotics.

Therapies for Mental Health Problems

The following therapies can help alleviate IBS symptoms linked to mental health issues:

• Talk therapy can help reduce stress and improve IBS symptoms. Two common types of talk therapy for IBS are cognitive behavioral therapy and psychodynamic therapy. Cognitive behavioral therapy emphasizes the connection between thoughts and actions, while psychodynamic therapy explores how emotions influence IBS symptoms. This approach often incorporates relaxation and stress management techniques.
• Hypnotherapy may assist in relaxing the muscles of the colon.
• Mindfulness training encourages individuals to concentrate on present sensations and avoid catastrophizing, or overthinking the implications of those sensations.

How does stress affect IBS?

Stress can trigger colon spasms in individuals with IBS. The colon is connected to the brain through numerous nerves, which regulate its normal contractions and can lead to abdominal discomfort during stressful periods. For those with IBS, the colon may react excessively to even minor stressors or conflicts. Additionally, stress heightens awareness of sensations in the colon, which can exacerbate IBS symptoms and further increase stress levels. To manage stress, consider the following options:

• Engaging in stress reduction and relaxation techniques like meditation
• Seeking counseling and support
• Participating in regular physical activities such as walking or yoga
• Limiting stressful situations whenever possible
• Ensuring adequate sleep.