Irritable Bowel Syndrome (IBS)

Introduction

Irritable bowel syndrome (IBS) is a very common gastrointestinal (GI) disorder. It is also referred to as nervous indigestion, spastic colon, and functional bowel disease. IBS is defined by the symptoms of abdominal pain and diarrhea or constipation for a prolonged period of time.

The cause of IBS is unknown. It is more common in women and appears to be associated with many factors, including emotional stress. For some people, IBS is a chronic lifelong condition. There is no cure for IBS. However, symptoms may be managed with lifestyle changes, medications, and dietary alterations.

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Anatomy

Your body absorbs nutrients and removes waste products via your digestive system. Whenever you eat and drink, food travels through your digestive system for processing. As water from the waste product is absorbed, the product becomes more solid and forms a stool or feces. It is eventually eliminated from your body when you have a bowel movement.

After you swallow food, it moves through your esophagus and into your stomach. Chemicals in your stomach break down the food into a liquid form. The processed liquid travels from your stomach to your small intestine. Your small intestine breaks down the liquid even further so that your body can absorb the nutrients from the food you ate. The remaining waste products from the small intestine travel to the large intestine.

Your large intestine, also called the large bowel or colon, is a tube that is about 5 feet long and 3 or 4 inches around. The lower GI tract is divided into sections, including the cecum, ascending colon, transverse colon, descending colon, sigmoid colon, rectum, anal canal, and anus. The appendix is located on the cecum, but it does not serve a purpose in the digestive process.

The first part of the colon absorbs water and nutrients from the waste products that come from the small intestine. As the colon absorbs water from the waste product, the product becomes more solid and forms a stool.

The large intestine moves the stool through the large intestine into the sigmoid colon, where it may be stored before traveling to the rectum. The rectum is the final 6-inch section of your digestive tract. No significant nutrient absorption occurs in the rectum or anal canal.

From the rectum, the stool moves through the anal canal. It passes out of your body through your anus when you have a bowel movement.

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Causes

The cause of IBS is unknown. It appears that abnormal muscle movement patterns in the GI tract and changes in the communication system between the brain and the GI tract may lead to the condition.

Researchers suspect IBS may be triggered by dietary factors including a low-fiber diet, high-fat foods, carbonated drinks, fructose, sorbitol, and dairy products. It also appears that certain medications, alcohol, smoking, and gastroenteritis may lead to IBS.

IBS is more common in women. Doctors suspect that a hormonal component may trigger IBS. Some women report IBS at the time of menstruation. Many people that experience emotional stress, trauma, sexual assault, or intimate violence develop IBS.

IBS most frequently occurs between adolescence and young adulthood, although it may occur at any age. IBS is not a contagious or inherited condition. It does not cause cancer.

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Symptoms

IBS causes either frequent diarrhea or constipation for a prolonged period of time. Your abdomen may feel tender or painful. The pain may be relieved following a bowel movement. You may pass mucus with your stool and your stools may look different than they usually do. Your stomach may feel full, bloated, or distended.

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Diagnosis

Your doctor can diagnose IBS by reviewing your medical history and conducting a physical examination. You should tell your doctor about your symptoms, how long you have experienced the symptoms, and possible contributing factors.

There is no single test to identify IBS. A diagnosis of IBS is made by exclusion, meaning ruling out other diseases or conditions with similar symptoms first. A diagnosis of IBS generally requires symptom duration of 12 weeks or more.

Your doctor may order tests to help determine the diagnosis. Tests may include blood tests, stool tests, and imaging studies. Imaging studies commonly include a sigmoidoscopy or colonoscopy.

A flexible sigmoidoscopy is used to view the rectum and part of the colon for cancer or polyps. A sigmoidoscope is a thin tube with a light and viewing instrument. It is about two feet long. The sigmoidoscope is placed in the colon, through the anus. This test can be uncomfortable, but should not be painful.

A colonoscopy is used to view the entire colon. A colonoscope is similar to a sigmoidoscope, but it is much longer. A colonoscope allows a doctor to examine the colon for cancer or polyps. A tissue sample or biopsy can be taken with the colonscope. A colonoscopy can be uncomfortable, and you will receive medication to relax you prior to and during the test.

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Treatment

There is no cure for IBS. Treatment is aimed at relieving symptoms and minimizing flare-ups. Treatments are different for everyone, depending on their triggers for IBS. Treatment may include dietary changes, lifestyle changes, counseling, and medications.

Dietary changes may include increasing your fiber intake and avoiding foods that irritate your digestive system. It can be helpful to avoid cigarette smoking, caffeine products, and alcohol. Emotional stress or mental health issues can be addressed with counseling, medications, or both. Regular exercise can also help. Your doctor may recommend over-the-counter medication or prescription medication to relieve stomach spasms and diarrhea.

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Prevention

Because the cause of IBS is unknown, specific prevention measures are unknown. It appears that some people may reduce their symptoms by making lifestyle and dietary changes. It is important to attend your doctor appointments so that you may both work on recognizing what triggers your symptoms to best establish a treatment plan for you.

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Am I at Risk

Because the cause of IBS is unknown, risk factors cannot be readily identified. However, it appears that several factors may contribute to IBS.

Possible contributing factors for IBS:

• IBS occurs more frequently in women than men.
• People in their teens through early adulthood are more likely to develop IBS.
• Emotional stress, emotional trauma, sexual assault, intimate violence, and some mental health disorders appear to be associated with IBS.
• It is suspected that dietary factors may play a role in the development of IBS including a low-fiber diet, high-fat diet, dairy products, sorbitol, fructose, and carbonated beverages.
• It appears that smoking and consuming alcohol may lead to IBS.
• Certain medications including select antidepressants, antibiotics, and medications made with sorbitol may be associated with IBS.
• There may be a link between experiencing gastroenteritis (infectious stomach flu, traveler’s diarrhea, or food poisoning) and IBS.

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Complications

IBS can cause loss of appetite, dehydration, or malnutrition because of food aversion. Diarrhea can occur frequently and abruptly. This may disrupt your personal lifestyle and interfere with your work or leisure activities.

The experience of IBS can be frustrating and an emotional process for some people and their loved ones. It is important that you receive support from a positive source. Some people find comfort in their family, friends, co-workers, and faith. Support groups for people with digestive conditions are another good option. They can be a good source of information and support from people who understand what you are experiencing. Ask your doctor for support group locations in your area.

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