Functional Disorder: Irritable Bowel Syndrome Explained

Irritable Bowel Syndrome (IBS) is a common functional disorder that affects the digestive system, specifically the large intestine. This condition is characterized by a group of symptoms that occur together, including repeated pain in your abdomen and changes in your bowel movements, which may be diarrhea, constipation, or both. With IBS, you have these problems without any visible signs of damage or disease in your digestive tract.

IBS is a chronic condition that you will need to manage long term. Even though signs and symptoms are uncomfortable, IBS — unlike ulcerative colitis and Crohn's disease, which are forms of inflammatory bowel disease — doesn't cause changes in bowel tissue or increase your risk of colorectal cancer.

Understanding IBS

IBS is a disorder that affects the large intestine. It is classified as a functional gastrointestinal disorder, which means that the body's normal activities, such as digestion, are disrupted without any evidence of a structural defect. This means that while the digestive system looks normal, it doesn't work as it should.

IBS is not a disease; it's a syndrome, meaning it's a group of symptoms put together. Because it's a syndrome, not all patients with IBS have the same symptoms. The symptoms vary from person to person and often resemble those of other diseases.

Prevalence of IBS

IBS is one of the most common disorders that doctors see. It's estimated that 10 to 15 percent of the general population experiences IBS symptoms. Yet, only 5 to 7 percent of adults have been diagnosed with the disease. IBS affects people of all ages, including children. It's more common in women than men.

Many people have mild signs and symptoms of IBS. Sometimes the symptoms are severe enough to significantly impact a person's ability to work, travel, and attend social events. The discomfort of IBS may lead to feelings of anxiety and depression.

Types of IBS

There are four types of IBS, each with different symptoms. The types are IBS-D (diarrhea-predominant), IBS-C (constipation-predominant), IBS-M (mixed), and IBS-U (unclassified). The type of IBS a person has is identified by the pattern of their symptoms.

IBS-D is characterized by frequent, loose stools and abdominal pain. IBS-C is characterized by infrequent, hard stools and abdominal pain. IBS-M is characterized by alternating between constipation and diarrhea. IBS-U is used when the symptoms don't fit into the other categories.

Symptoms of IBS

The symptoms of IBS can vary widely from person to person and often resemble other diseases. Among the most common are abdominal pain or cramping, a bloated feeling, gas, diarrhea or constipation — sometimes alternating bouts of constipation and diarrhea — and mucus in the stool.

Most people with IBS experience times when the signs and symptoms are worse and times when they improve or even disappear completely. Symptoms often get worse after meals. A flare-up may last from 2 to 4 days, and then symptoms either improve or go away completely.

Abdominal Pain

Abdominal pain is one of the hallmark symptoms of IBS. The pain typically occurs in the lower abdomen, but the location can vary. The pain often begins after eating and may be relieved by having a bowel movement.

The nature of the pain can also vary. Some people describe it as a sharp, stabbing pain, while others describe it as a cramp or a dull ache. The intensity of the pain can range from mild to severe.

Changes in Bowel Movements

People with IBS often experience changes in bowel movements. This can include diarrhea, constipation, or a combination of both. Some people may have loose stools, while others may struggle to pass hard, dry stools.

The frequency of bowel movements can also change. Some people may have bowel movements several times a day, while others may have them only once or twice a week. These changes in bowel movements can cause a feeling of incomplete evacuation, which is the sensation of needing to pass a bowel movement even after having one.

Causes of IBS

The exact cause of IBS is not known. Researchers believe it's due to a combination of physical and mental health problems. These include abnormalities in the gastrointestinal nervous system, an increased sensitivity to pain, changes in gut bacteria, and mental health disorders like anxiety and depression.

It's also believed that certain factors can trigger IBS symptoms. These include food, stress, hormonal changes (women are more likely to have IBS, and their symptoms are often worse during their menstrual periods), and certain medications (particularly antibiotics, which can disrupt the balance of bacteria in the gut).

Role of the Gastrointestinal Nervous System

The gastrointestinal nervous system plays a crucial role in the functioning of the gut. It controls the movement of food through the digestive tract and the secretion of digestive juices. In people with IBS, the gastrointestinal nervous system may be overly sensitive, causing the gut to overreact to normal triggers, such as eating or stress.

This overreaction can lead to the symptoms of IBS. For example, the gut may contract too strongly or too quickly, leading to diarrhea. Or it may contract too slowly, leading to constipation.

Changes in Gut Bacteria

The gut is home to trillions of bacteria, known as the gut microbiota. These bacteria play a crucial role in digestion, immune function, and overall health. Some research suggests that people with IBS may have an imbalance in their gut bacteria, known as dysbiosis.

This dysbiosis may contribute to the symptoms of IBS. For example, certain types of bacteria may produce more gas, leading to bloating and discomfort. Or the imbalance may lead to inflammation in the gut, which can cause pain and changes in bowel movements.

Diagnosis of IBS

There's no specific test to diagnose IBS. The diagnosis is usually based on symptoms. Your doctor may be able to diagnose IBS based on your symptoms alone, or they may use other tests to rule out other conditions.

These tests may include blood tests, stool tests, and imaging tests, such as an X-ray or CT scan. In some cases, your doctor may refer you to a gastroenterologist, a doctor who specializes in digestive diseases.

Rome Criteria

The Rome criteria are a set of symptoms that doctors use to diagnose IBS. According to the Rome IV criteria, a person must have recurrent abdominal pain, on average, at least one day per week in the last three months, associated with two or more of the following criteria: related to defecation, associated with a change in frequency of stool, or associated with a change in form (appearance) of stool.

The criteria must be fulfilled for the last three months with symptom onset at least six months before diagnosis. The Rome criteria were developed to standardize the diagnosis of IBS and other functional gastrointestinal disorders.

Exclusion of Other Conditions

Because the symptoms of IBS can resemble other diseases, your doctor may perform tests to rule out other conditions. These may include inflammatory bowel disease, celiac disease, and colorectal cancer.

These tests may include blood tests to check for anemia and inflammation, stool tests to check for infections or malabsorption, and imaging tests to look for abnormalities in the digestive tract. In some cases, your doctor may perform a colonoscopy, a procedure that allows them to examine the inside of your colon.

Treatment of IBS

There's no cure for IBS, but treatments can often help to manage symptoms. The best approach depends on the nature of your symptoms, your personal preferences, and how you respond to treatment. Treatment options include changes in diet and lifestyle, medications, and psychological therapies.

It's important to work with your healthcare provider to develop a treatment plan that fits your needs. This may involve trying different treatments to see what works best for you. It may also involve regular follow-up appointments to monitor your symptoms and adjust your treatment as needed.

Diet and Lifestyle Changes

Many people with IBS find that their symptoms improve with changes in diet and lifestyle. This may include eating a healthy diet, getting regular exercise, and managing stress.

Some people find that certain foods trigger their IBS symptoms. These can vary from person to person, but common triggers include fatty foods, spicy foods, alcohol, caffeine, and gas-producing foods like beans and cabbage. Keeping a food diary can help you identify your personal triggers.

Medications

Several medications are available to treat IBS symptoms. The choice of medication depends on the nature of your symptoms. For example, if you have IBS with constipation, your doctor may recommend a laxative. If you have IBS with diarrhea, they may recommend an anti-diarrheal medication.

Other medications used to treat IBS include antispasmodics, which can help to relieve abdominal pain, and antidepressants, which can help to relieve both pain and bowel problems. In some cases, your doctor may recommend a medication specifically approved for the treatment of IBS, such as lubiprostone (Amitiza) or linaclotide (Linzess).

Psychological Therapies

Because stress and anxiety can trigger IBS symptoms, psychological therapies can be an effective part of treatment. These may include cognitive behavioral therapy, which can help you to manage stress and cope with your symptoms, and relaxation techniques, such as deep breathing or progressive muscle relaxation.

Some people with IBS also find that support groups are helpful. These groups provide a place to share experiences, get advice, and receive emotional support. Ask your healthcare provider if there are any IBS support groups in your area.

Living with IBS

Living with IBS can be challenging, but with the right treatment and support, most people with IBS can lead active, fulfilling lives. It's important to work closely with your healthcare provider to manage your symptoms and adjust your treatment as needed.

Remember that it's okay to seek help. If you're feeling stressed or overwhelmed, consider talking to a mental health professional. They can provide strategies to help you cope with the emotional aspects of living with a chronic illness.

Managing Flare-Ups

Even with treatment, you may have times when your IBS symptoms flare up. During these times, it's important to take care of yourself. This may include resting, eating a bland diet, and avoiding stress as much as possible.

Keep in mind that everyone's experience with IBS is different. What works for one person may not work for another. It may take time to find the best approach for you.

Impact on Quality of Life

IBS can have a significant impact on quality of life. The symptoms can be uncomfortable and inconvenient, and they can interfere with work, school, and social activities. However, with effective treatment and self-care, most people with IBS can manage their symptoms and lead active, fulfilling lives.

It's important to remember that you're not alone. There are many resources available to help you manage your IBS, including healthcare providers, support groups, and online communities. Don't hesitate to reach out for help if you need it.