Irritable bowel syndrome (IBS)
Irritable Bowel Syndrome - Irritable bowel syndrome (IBS) is a functional GI disorder characterized by abdominal pain and altered bowel habits in the absence of demonstrable organic pathology. Osler coined the term mucous colitis in 1892 when he wrote of a disorder of mucorrhea and abdominal colic with a high incidence in patients with coincident psychopathology. Since that time, the syndrome has been referred to by sundry terms, including spastic, irritable, and nervous colon.
Irritable bowel syndrome (IBS) is one of the most common disorders that physicians see. Yet it's also one that many people aren't comfortable talking about. IBS is characterized by abdominal pain or cramping and changes in bowel function — including bloating, gas, diarrhea and constipation — problems most people don't like to discuss. What's more, for many years IBS was considered a psychological rather than a physical problem.
The disorder accounts for more than one out of every 10 doctor visits. For most people, signs and symptoms of irritable bowel disease are mild. Only a small percentage of people with IBS have severe signs and symptoms.
Fortunately, unlike more serious intestinal diseases such as ulcerative colitis and Crohn disease, IBS doesn't cause inflammation or changes in bowel tissue or increase your risk of colorectal cancer. In many cases, you can control IBS by managing your diet, lifestyle and stress.
Signs and symptoms of IBS vary widely from one person to another and often occur with many other diseases. Among the most common are:
Like many people, you may have only mild signs and symptoms of IBS. Sometimes these problems can be disabling, however. In some cases, you may have severe signs and symptoms that don't respond well to medical treatment.
For most people, IBS is a chronic condition, although there will likely be times when signs and symptoms are worse and times when they improve or even disappear completely.
Many people live with irritable bowel syndrome (IBS). Symptoms range from an occasional upset stomach to almost constant pain.
The walls of the intestines are lined with layers of muscle that contract and relax as they move food from your stomach through your intestinal tract to the rectum. Normally, these muscles contract and relax in a coordinated rhythm. But if you have IBS, the contractions are stronger and last longer than normal. Food is forced through your intestines more quickly, causing gas, bloating and diarrhea. In some cases, however, the opposite occurs. Food passage slows, and stools become hard and dry.
No one knows exactly what causes IBS. Some researchers believe IBS is caused by changes in the nerves that control sensation or muscle contractions in the bowel. Others believe the central nervous system may affect the colon. And because women are two to three times more likely than men to have IBS, researchers believe that hormonal changes also play a role. Also, many women find that signs and symptoms are worse during or around their menstrual periods.
For reasons that still aren't clear, if you have IBS you probably react strongly to stimuli that don't bother other people. Triggers for IBS can range from gas or pressure on your intestines to certain foods, medications or emotions. For instance, chocolate, milk and alcohol might cause constipation or diarrhea. And the least bit of stress might send your colon into spasms.
If you're like most people with IBS, you probably find that your signs and symptoms are worse or more frequent during stressful events, such as a change in your daily routine or family arguments. But while stress may aggravate symptoms, it doesn't cause them.
Sometimes another illness, such as an acute episode of infectious diarrhea (gastroenteritis) can trigger IBS. Antibiotic use also may be a factor because antibiotics disrupt the normal bacterial flora living in your bowel. Excessive use of laxatives and even some antidiarrheal medications may contribute to the problem as well.
If you experience cramping and bloating mainly after eating dairy products or sugar-free gum or candies, the problem may not be irritable bowel syndrome. Instead, your body may not be able to tolerate the sugar (lactose) in dairy products or the artificial sweetener sorbitol.
Many people have occasional symptoms of IBS, but you're more likely to have IBS if you're young and female. IBS typically begins around age 20. Overall, two to three times as many women as men have the condition.
When to seek medical advice
It's important to see your doctor if you have a persistent change in bowel habits or if you have any other symptoms of IBS.
Your doctor may be able to help you find ways to relieve symptoms as well as rule out other, more serious colon conditions, such as ulcerative colitis and Crohn's disease, which are forms of inflammatory bowel disease, and colon cancer. He or she can also help you avoid possible complications from problems such as chronic diarrhea.
Screening and diagnosis
A diagnosis of IBS depends largely on a complete medical history and physical exam. Your doctor may also recommend conducting several tests, including stool studies to check for infection or malabsorption problems. He or she may perform a flexible sigmoidoscopy — a test that examines the lower part of the colon (sigmoid) with a flexible, lighted tube (sigmoidoscope).
In some cases, your doctor may perform a colonoscopy, a diagnostic test in which a small, flexible tube is used to examine the entire length of the colon. These tests help rule out more serious conditions such as ulcerative colitis, Crohn's disease and colorectal cancer.
You may also have tests to determine whether you're lactose intolerant. Lactase is an enzyme you need to digest the sugar found in dairy products. If you lack this enzyme, you may have problems similar to those caused by IBS, including abdominal pain, gas and diarrhea. To find out if this is the cause of your symptoms, your doctor may order a breath test or ask you to exclude milk and milk products from your diet for several weeks to see if a lactose intolerance is causing your symptoms. Celiac disease (nontropical sprue) is a sensitivity to wheat protein that may cause symptoms like IBS as well. Blood tests may help rule out that disorder.
Because there are usually no physical signs of disease in IBS, diagnosis is often a process of elimination. To help in this process, researchers have developed diagnostic criteria, known as Rome criteria, for IBS and other functional gastrointestinal disorders — conditions in which the bowel appears normal but doesn't function normally.
According to these criteria, you must have certain signs and symptoms before a doctor diagnoses IBS. The most important are abdominal pain, and diarrhea or constipation lasting at least three months. You also need to have at least two of the following, one-fourth or more of the time:
Both diarrhea and constipation can aggravate hemorrhoids. In addition, signs and symptoms of IBS can interfere with your work, your relationships with friends and family, and your ability to live your life to the fullest. At times, you may feel discouraged or depressed.
Because it's still not clear what causes IBS, treatment focuses on the relief of symptoms so that you can live your life as fully and normally as possible.
In most cases, you can successfully control mild symptoms of IBS by learning to manage stress and making changes in your diet and lifestyle. But if your problems are moderate or severe, you may need more help than lifestyle changes alone can offer.
For moderate IBS, your doctor may suggest taking fiber supplements such as psyllium (Metamucil) or methylcellulose (Citrucel) with fluids, to help control constipation and over-the-counter medications such as loperamide (Imodium) to help control diarrhea. In some cases, you may need drugs that affect certain activities of the nervous system (anticholinergics) to relieve painful bowel spasms. If so, follow-up with your doctor is very important.
If your symptoms include pain and depression, your doctor may recommend a tricyclic antidepressant or a selective serotonin reuptake inhibitor (SSRI). These medications help relieve depression as well as inhibit the activity of neurons that control the intestines. For diarrhea and abdominal pain, your doctor may suggest tricyclic antidepressants such as imipramine (Tofranil) and amitriptyline (Elavil). Side effects of these drugs include drowsiness and constipation.
Selective serotonin reuptake inhibitors such as fluoxetine (Prozac, Sarafem) or paroxetine (Paxil) may be helpful if you're depressed and have pain and constipation. If these medications don't work, you may have better results from counseling. If you have severe IBS, it's important to receive ongoing treatment and support from your physician.
Alosetron (Lotronex) is a nerve receptor antagonist that's supposed to relax the colon and slow the movement of waste through the lower bowel. But the drug was pulled from the market just nine months after its approval when it was linked to at least four deaths and severe side effects in 197 people.
Lotronex — with a number of restrictions. The drug can be prescribed only by doctors enrolled in a special program and is intended for severe cases that haven't responded to other treatments. Lotronex is not approved for use by men or for women who don't have the diarrhea-predominant form of IBS.
Tegaserod (Zelnorm) iIt's approved only for short-term use in women, and has not been approved for use in men. Tegaserod imitates the action of the neurotransmitter serotonin and helps to coordinate the nerves and muscles in the intestine.