Irritable bowel syndrome (IBS)
Stan Nikitin, PharmD Candidate 2011
Stan Nikitin, PharmD Candidate 2011
April is IBS month, and you may be wondering “what exactly is IBS?” IBS stands for irritable bowel syndrome, which is a disorder affecting the large intestine, also called the colon. It's one of the most commonly diagnosed gastrointestinal conditions, affecting 55 million Americans. This means about 1 in 6 people have symptoms of IBS! Women tend to be affected more often than men. The exact cause of IBS is unknown. There are many hypotheses and the causes may include genetics, problems with the intestinal muscles, infections, stress or other psychological factors.1-3
Symptoms of IBS
The symptoms of IBS usually begin in adolescence or early adulthood, but can occur at any age. Symptoms can vary in severity, but the good news is that most people with IBS have mild symptoms. Abdominal pain, fullness, flatulence (gas), and bloating that have been present for at least 6 months are the main symptoms of IBS.2 While different people are affected differently, the symptoms can also include:
· Cramping - pain or tightness in the abdomen
· Changes in bowel movements
· Constipation or diarrhea - both can occur, but mostly it is one or the other
· Mucus in the stool4
Symptoms are more likely to occur after meals, can come and go, and may be milder or disappear completely following a bowel movement.
All people are affected differently. For most people IBS is a chronic condition, but symptoms can come and go, improve or worsen, and be present constantly or intermittently.
The symptoms of IBS may seem daunting and scary, but fortunately, do not cause any permanent damage to the colon. For example, IBS does not increase the risk for colorectal cancer. Also, IBS does not cause any inflammation or changes in bowel tissue unlike the more serious intestinal diseases such as Crohn’s disease or ulcerative colitis.4
Diagnosis
IBS is largely diagnosed based on symptoms. Your doctor will diagnose IBS based on your symptoms, medical history, and a physical exam. If any tests are necessary, they are to rule out any other conditions. The tests may be necessary especially if there is weight loss, rectal bleeding, fever, nausea or recurrent vomiting, abdominal pain that is not completely relieved by a bowel movement, diarrhea that is persistent or awakens you from sleep, or if symptom onset occurs after the age of 50. Some of the tests can include:4
The symptoms of IBS may seem daunting and scary, but fortunately, do not cause any permanent damage to the colon. For example, IBS does not increase the risk for colorectal cancer. Also, IBS does not cause any inflammation or changes in bowel tissue unlike the more serious intestinal diseases such as Crohn’s disease or ulcerative colitis.4
Diagnosis
IBS is largely diagnosed based on symptoms. Your doctor will diagnose IBS based on your symptoms, medical history, and a physical exam. If any tests are necessary, they are to rule out any other conditions. The tests may be necessary especially if there is weight loss, rectal bleeding, fever, nausea or recurrent vomiting, abdominal pain that is not completely relieved by a bowel movement, diarrhea that is persistent or awakens you from sleep, or if symptom onset occurs after the age of 50. Some of the tests can include:4
· Blood tests - check for blood loss or deficiency, inflammation, and Celiac disease (symptoms of which may resemble IBS)
· Stool analysis - checks for blood in the stool and certain infections (for example, parasites).
· Sigmoidoscopy or colonoscopy - allows the doctor to look inside the intestine for abnormal growths, bleeding, inflammation, and other irregularities
· Lactose intolerance test - tests for lactase deficiency. Some people lack the enzyme lactase, which breaks down dairy sugars. Affected people may have symptoms resembling IBS after eating or drinking dairy products. Your doctor may instruct you to avoid dairy products for several weeks to rule out lactase deficiency.
Treatment
While IBS is a chronic condition, it is manageable. The focus of treatment is to relieve symptoms. Diet and lifestyle changes can help you manage IBS. More severe forms of IBS may require the use of medications that can help alleviate symptoms.
Diet and Lifestyle Changes
Making changes to your diet and lifestyle may help relieve IBS symptoms.
Lifestyle changes:
· Exercise - exercise may reduce anxiety and stress, which in turn may help relieve IBS symptoms.
· Improved sleep habits – an erratic sleep schedule may worsen IBS symptoms. Improving your sleep habits may help. Try to go to bed at the same time each day and get plenty of sleep to avoid fatigue and potential stress.
Dietary changes:
· Eat at regular times - try to eat at the same time each day. Do not skip meals. Avoid large meals.
· Avoid problem foods - avoid foods that you know for certain trigger your IBS symptoms. Avoid fatty foods or ones with high sugar content. Artificial sweeteners (such as sorbitol and mannitol) may be found in sugar-free gum or other foods and can be problematic. Certain foods and drinks stimulate the intestines. Caffeine containing products (coffee, tea, and energy drinks) are notorious for this effect. Carbonated drinks like soda can produce gas. Some other problem foods may include whole grains, chocolate, or alcohol. Vegetables like broccoli, cauliflower, cabbage, and beans can increase gas. Dairy products may cause much discomfort to lactose intolerant people. See lactose intolerance test above.1,2,4
· Foods rich in fiber - while fiber-rich foods such as fruits, vegetables, and beans may help with constipation for some people, they can make symptoms worse for others.
· Drink plenty of water - water is always best. Remember that coffee, tea, alcohol, soda, and dairy products like milk can worsen the symptoms.
Medication
Medication use in IBS should target your most upsetting symptoms. The lowest dose possible that relieves your symptoms is usually recommended. If you are considering using over-the-counter medication, discuss such use with your doctor or pharmacist before selecting one. Explaining your symptoms to your doctor or pharmacist can help the healthcare professional recommend the right medication for you.
Medication use in IBS should target your most upsetting symptoms. The lowest dose possible that relieves your symptoms is usually recommended. If you are considering using over-the-counter medication, discuss such use with your doctor or pharmacist before selecting one. Explaining your symptoms to your doctor or pharmacist can help the healthcare professional recommend the right medication for you.
Over-the-counter (OTC) medications
· Immodium (loperamide) - loperamide decreases the frequency of bowel movements, which may be of relief to some with diarrhea, but it does not help with other IBS symptoms.
· Fiber supplements - fiber supplements such as Metamucil may help with constipation- predominant IBS, but can make symptoms worse for people with diarrhea-predominant IBS.
· Laxatives - there are various laxative types that work in different ways to help with constipation. Discuss with your doctor or pharmacist which laxative may be appropriate for you.
Prescription medications
Diarrhea-Predominant IBS:
· Antispasmodic drugs may help with intestinal spasms and cramping.2-5 These drugs relax the smooth muscles of the intestine using an anticholinergic mechanism. Some examples of these medications are hyoscyamine and dicyclomine. Common side effects are drowsiness, dry mouth, blurred vision, constipation, and urinary retention.6
· Cholestyramine may be helpful to people with bile acid absorption problems.1,3 The most common side effect reported with cholestyramine use is constipation.6
· Lotronex (alosetron) is approved for women only with diarrhea-predominant IBS and has restricted use. It can only be prescribed by a doctor enrolled in a special program.1,4,5 The most common side effect reported is constipation.6
Constipation Predominant IBS:
· Amitiza (lubiprostone) is approved for women 18 and older only who have constipation predominant IBS. 4, 5 Common side effects are nausea, headache, and diarrhea.6
Other therapies:
· Xifaxan (rifaximin) is an oral non-absorbable (acts in the gastrointestinal tract without getting into the bloodstream) antibiotic that may be effective for global IBS symptoms, especially for diarrhea-predominant IBS. 7 This drug is minimally absorbed and stays in the intestine. Common side effects are flatulence (gas), nausea, dizziness, and fatigue.6
· For difficult to treat conditions your doctor may prescribe antidepressants. These can include 2 drug classes: tricyclic antidepressants (TCAs) and selective serotonin reuptake inhibitors (SSRIs). These can be helpful in relieving abdominal pain and slowing down intestinal transit time.1,2,4,5 Common side effects with TCAs are drowsiness, dry mouth, blurred vision, constipation, urinary retention, and weight gain.6 Common side effects with SSRIs are headache, sleepiness, insomnia, nausea, diarrhea, and sexual dysfunction.6
· Other treatment options exist such as probiotics, peppermint oil, herbal therapies and acupuncture. While these treatments may be helpful and beneficial to some, there’s little medical evidence about their effectiveness.
What to expect
Irritable bowel syndrome can be a chronic, lifelong condition and has no known cure. Many people with IBS learn to manage the condition and still lead active, fruitful lives. Understandably, the condition may not be easy to discuss, but be open about your communication with healthcare professionals. Be informed, ask lots of questions, and remember that healthcare professionals are there to help! Be your own advocate and take charge in the management of your IBS!
For more information:
· Mayo Clinic
http://www.mayoclinic.com/health/irritable-bowel-syndrome/DS00106
http://www.mayoclinic.com/health/irritable-bowel-syndrome/DS00106
· WebMD
http://www.webmd.com/ibs/default.htm
http://www.webmd.com/ibs/default.htm
· WebMD Support Group Message Board
http://exchanges.webmd.com/ibs-support-group
http://exchanges.webmd.com/ibs-support-group
· National Institutes of Health
http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001292
http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001292
· U.S. National Library of Medicine Interactive Tutorial http://www.nlm.nih.gov/medlineplus/tutorials/irritablebowelsyndrome/htm/index.htm
· National Digestive Diseases Information Clearinghouse
http://digestive.niddk.nih.gov/ddiseases/pubs/ibs/
http://digestive.niddk.nih.gov/ddiseases/pubs/ibs/
· American College of Gastroenterology
http://www.acg.gi.org/patients/ibsrelief/index.asp
http://www.acg.gi.org/patients/ibsrelief/index.asp
References
1. Spruill WJ, Wade WE. Diarrhea, constipation, and irritable bowel syndrome. In: DiPiro JT, Talbert RL, Yee G, Matzke GR, Wells BG, Posey LM, eds. Pharmacotherapy: A Pathophysiologic Approach. 7th ed. New York, NY: McGraw-Hill; 2008:628-631.
2. U.S. National Library of Medicine, National Institutes of Health. Irritable bowel syndrome. http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001292. Updated July 7, 2010. Accessed February 24, 2011.
3. WebMD. Irritable bowel syndrome health center. http://www.webmd.com/ibs/default.htm. Updated May 23, 2008. Accessed February 24, 2011.
4. Mayo Clinic. Irritable bowel syndrome. http://www.mayoclinic.com/health/irritable-bowel-syndrome/DS00106. Updated July 29, 2009. Accessed February 24, 2011.
5. Wald, A. Treatment of irritable bowel syndrome. In: UpToDate, Talley NJ (Ed), UpToDate, Waltham, MA, 2011. Accessed February 24, 2011.
6. Wickersham RM, ed. Drug Facts and Comparisons. St. Louis, MO: Wolters Kluwer Health; 2011. http://online.factsandcomparisons.com. Accessed March 2, 2011.
1. Spruill WJ, Wade WE. Diarrhea, constipation, and irritable bowel syndrome. In: DiPiro JT, Talbert RL, Yee G, Matzke GR, Wells BG, Posey LM, eds. Pharmacotherapy: A Pathophysiologic Approach. 7th ed. New York, NY: McGraw-Hill; 2008:628-631.
2. U.S. National Library of Medicine, National Institutes of Health. Irritable bowel syndrome. http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001292. Updated July 7, 2010. Accessed February 24, 2011.
3. WebMD. Irritable bowel syndrome health center. http://www.webmd.com/ibs/default.htm. Updated May 23, 2008. Accessed February 24, 2011.
4. Mayo Clinic. Irritable bowel syndrome. http://www.mayoclinic.com/health/irritable-bowel-syndrome/DS00106. Updated July 29, 2009. Accessed February 24, 2011.
5. Wald, A. Treatment of irritable bowel syndrome. In: UpToDate, Talley NJ (Ed), UpToDate, Waltham, MA, 2011. Accessed February 24, 2011.
6. Wickersham RM, ed. Drug Facts and Comparisons. St. Louis, MO: Wolters Kluwer Health; 2011. http://online.factsandcomparisons.com. Accessed March 2, 2011.
7. American College of Gastroenterology. ACG releases evidence-based systematic review on management of irritable bowel syndrome. http://www.acg.gi.org/media/releases/december182008.asp. Published December 18, 2008. Accessed March 14, 2011.
