Irritable bowel syndrome (IBS) is a common disorder that affects the large intestine (colon). Irritable bowel syndrome commonly causes cramping, abdominal pain, bloating, gas, diarrhea and constipation. IBS is a chronic condition that you will need to manage long term.
The signs and symptoms of irritable bowel syndrome can vary widely from person to person and often resemble those of other diseases. Among the most common are:
- Abdominal pain or cramping
- A bloated feeling
- Diarrhea or constipation — sometimes alternating bouts of constipation and diarrhea
- Mucus in the stool
For most people, IBS is a chronic condition, although there will likely be times when the signs and symptoms are worse and times when they improve or even disappear completely.
When to see a doctor
Yet it’s important to see your doctor if you have a persistent change in bowel habits or if you have any other signs or symptoms of IBS because these may indicate a more serious condition, such as colon cancer.
Symptoms that may indicate a more serious condition include:
- Rectal bleeding
- Abdominal pain that progresses or occurs at night
- Weight loss
Many people have occasional signs and symptoms of irritable bowel syndrome, but you’re more likely to have IBS if you:
- Are young. IBS tends to occur in people under age 45.
- Are female. Overall, about twice as many women as men have the condition.
- Have a family history of IBS. Studies suggest that people who have a family member with IBS may be at increased risk of the condition.
- Have a mental health problem. Anxiety, depression, a personality disorder and a history of childhood sexual abuse are risk factors. For women, domestic abuse may be a risk factor as well.
The influence of family history on IBS risk may be related to genes, shared factors in a family’s environment or both.
Diarrhea and constipation, both signs of irritable bowel syndrome, can aggravate hemorrhoids. In addition, if you avoid certain foods, you may not get enough of the nutrients you need, leading to malnourishment.
But the condition’s impact on your overall quality of life may be the most significant complication. These effects of IBS may cause you to feel you’re not living life to the fullest, leading to discouragement or depression.
Tests and diagnosis
A diagnosis of irritable bowel syndrome depends largely on a complete medical history and physical exam.
Criteria for making a diagnosis
- New onset after age 50
- Weight loss
- Rectal bleeding
- Nausea or recurrent vomiting
- Abdominal pain, especially if it’s not completely relieved by a bowel movement, or occurs at night
- Diarrhea that is persistent or awakens you from sleep
- Anemia related to low iron
If you fit the IBS criteria and don’t have any red flag signs or symptoms, your doctor may suggest a course of treatment without doing additional testing. But if you don’t respond to that treatment, you’ll likely require more tests.
Your doctor may recommend several tests, including stool studies to check for infection or problems with your intestine’s ability to take in the nutrients from food (malabsorption). You may undergo a number of tests to rule out other causes for your symptoms.
- Lactose intolerance tests.
- Breath tests.
- Blood tests.
- Stool tests. If you have chronic diarrhea, doctors may want to examine your stool for bacteria or parasites.
- Flexible sigmoidoscopy.
- X-ray (radiography). Sometimes doctors will use X-rays to obtain an image of your colon.
- Computerized tomography (CT) scan. CT scans produce cross-sectional X-ray images of internal organs. CT scans of your abdomen and pelvis may help your doctor rule out other causes of your symptoms, especially if you have abdominal pain.
- Lower GI series. In this test, doctors fill your large intestine with a liquid (barium) to make it easier to see any problems on the X-ray.
Treatments and drugs
- Eliminating high-gas foods. If you have bothersome bloating or are passing considerable amounts of gas, your doctor may suggest that you cut out such items as carbonated beverages, vegetables — especially cabbage, broccoli and cauliflower — and raw fruits.
- Eliminating gluten. Research shows that some people with IBS report improvement in diarrhea symptoms if they stop eating gluten (wheat, barley and rye). This recommendation remains controversial, and the evidence is not clear.
- Eliminating FODMAPs. Some people are sensitive to types of carbohydrates such as fructose, fructans, lactose and others, called FODMAPs (fermentable oligo-, di-, and monosaccharides and polyols). FODMAPs are found in certain grains, vegetables, fruits and dairy products. However, often people are not bothered by every FODMAP food. You may be able to get relief from your IBS symptoms on a strict low FODMAP diet and then reintroduce foods one at time.
- Fiber supplements. Taking fiber supplements, such as psyllium or methylcellulose, with fluids may help control constipation. Fiber obtained from food may cause much more bloating compared with a fiber supplement. If fiber doesn’t help symptoms, your doctor may prescribe an osmotic laxative such as milk of magnesia or polyethylene glycol.
- Anti-diarrheal medications. Over-the-counter medications, such as loperamide, can help control diarrhea. Some people will benefit from medications called bile acid binders, such as cholestyramine, colestipol or colesevelam, but these can lead to bloating.
- Anticholinergic and antispasmodic medications. These medications, such as hyoscyamine and dicyclomine can help relieve painful bowel spasms. They are sometimes used for people who have bouts of diarrhea, but they can worsen constipation and can lead to other symptoms, such as difficulty urinating. They should also be used with caution among people with glaucoma.
- Antidepressant medications. If your symptoms include pain or 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.
- Some people whose symptoms are due to an overgrowth of bacteria in their intestines may benefit from antibiotic treatment. Some people with symptoms of diarrhea have benefited from rifaximin, but more research is needed.
- You may benefit from counseling if you have depression or if stress tends to worsen your symptoms.
Medication specifically for IBS
Two medications are currently approved for specific cases of IBS:
- Alosetron. Alosetron is designed to relax the colon and slow the movement of waste through the lower bowel.
However, alosetron can be prescribed only by doctors enrolled in a special program and is intended for severe cases of diarrhea-predominant IBS in women who haven’t responded to other treatments. Alosetron is not approved for use by men. It has been linked to rare but important side effects, so it should only be considered when other treatments are not successful.
- Lubiprostone. Lubiprostone works by increasing fluid secretion in your small intestine to help with the passage of stool. It is approved for women age 18 and older who have IBS with constipation. Its effectiveness in men is not proved, nor its long-term safety. Common side effects include nausea, diarrhea and abdominal pain. Lubiprostone is generally prescribed only for women with IBS and severe constipation for whom other treatments haven’t been successful.
Lifestyle and home remedies
In many cases, simple changes in your diet and lifestyle can provide relief from irritable bowel syndrome. Although your body may not respond immediately to these changes, your goal is to find long-term, not temporary, solutions:
- Experiment with fiber. When you have irritable bowel syndrome, fiber can be a mixed blessing. Although it helps reduce constipation, it can also make gas and cramping worse. The best approach is to slowly increase the amount of fiber in your diet over a period of weeks. Examples of foods that contain fiber are whole grains, fruits, vegetables and beans. If your signs and symptoms remain the same or worse, tell your doctor. You may also want to talk to a dietitian.
- Avoid problem foods. If certain foods make your signs and symptoms worse, don’t eat them. These may include alcohol, chocolate, caffeinated beverages such as coffee and sodas, medications that contain caffeine, dairy products, and sugar-free sweeteners such as sorbitol or mannitol.
If gas is a problem for you, foods that might make symptoms worse include beans, cabbage, cauliflower and broccoli. Fatty foods also may be a problem for some people. Chewing gum or drinking through a straw can lead to swallowing air, causing more gas.
- Eat at regular times. Don’t skip meals, and try to eat about the same time each day to help regulate bowel function. If you have diarrhea, you may find that eating small, frequent meals makes you feel better. But if you’re constipated, eating larger amounts of high-fiber foods may help move food through your intestines.
- Take care with dairy products. If you’re lactose intolerant, try substituting yogurt for milk. Or use an enzyme product to help break down lactose. Consuming small amounts of milk products or combining them with other foods also may help. In some cases, though, you may need to stop eating dairy foods completely. If so, be sure to get enough protein, calcium and B vitamins from other sources.
- Drink plenty of liquids. Try to drink plenty of fluids every day. Water is best. Alcohol and beverages that contain caffeine stimulate your intestines and can make diarrhea worse, and carbonated drinks can produce gas.
- Exercise regularly. Exercise helps relieve depression and stress, stimulates normal contractions of your intestines, and can help you feel better about yourself. If you’ve been inactive, start slowly and gradually increase the amount of time you exercise. If you have other medical problems, check with your doctor before starting an exercise program.
- Use anti-diarrheal medications and laxatives with caution. If you try over-the-counter anti-diarrheal medications, such as Imodium or Kaopectate, use the lowest dose that helps. Imodium may be helpful if taken 20 to 30 minutes before eating, especially if you know that the food planned for your meal is likely to cause diarrhea.
In the long run, these medications can cause problems if you don’t use them correctly. The same is true of laxatives. If you have any questions about them, check with your doctor or pharmacist.
Anyone can experience digestive upset from worry or anxiety. But if you have irritable bowel syndrome, stress-related problems such as abdominal pain and diarrhea tend to occur more often and be more severe. Finding ways to deal with stress may help prevent or ease symptoms:
- Progressive relaxation exercises.
- Deep breathing.
- Mindfulness training.
- Other techniques. Set aside at least 20 minutes a day for any activity you find relaxing — listening to music, reading, playing computer games or just soaking in a warm bath.