Articles

The Gut of the Matter

By Janna Gordon, R.Ph., MBA.

Do you have a map in your head of every public rest room in a 10 mile radius of your home? Are you often confined to your home, passing by opportunities for social activities and dinners outside due to the need to be close to a rest room? Then you may be one of the 20% of adult Americans who suffer from the symptoms of Irritable Bowel Syndrome (IBS). Seem more often in women than men, some sources suggest that symptoms of IBS generally arise prior to the mid thirties, while other sources negate its prevalence based on age. Similar in name to Irritable Bowel Disease, IBS has not been linked to Crohn’s disease and ulcerative colitis. IBS is defined as a functional bowel disorder characterized by abdominal pain and changes in bowel habits, which are not associated with any abnormalities seen on routine clinical testing.

Symptoms of IBS include cramping, abdominal pain, bloating, constipation, and diarrhea. While abdominal pain, bloating, and discomfort are the primary symptoms of IBS, they can vary from person to person. Some patients are prone to constipation, while others primarily experience diarrhea. Others alternate between the two conditions. Symptoms may worsen over time or come and go.

The cause of IBS remains a mystery with one theory suggesting that people with IBS have a colon (large intestine) that is very sensitive and reactive to certain foods and stress. The immune system may also be involved. Other theories include:

• a colon that is spasmodic or temporarily stops working,
  
• the lining of the colon stops working properly by either not absorbing enough fluid leading to diarrhea, or by absorbing too much fluid resulting in constipation,
  
• the colon is especially sensitive to foods and stresses that may not bother another individual,
  
• colonic changes that are a result of serotonin changes in the gastrointestinal (GI) tract. The GI tract contains 95% of serotonin in the body. Research suggests that constipation dominant IBS (IBS-C) is associated with serotonin deficiency and diarrhea dominant IBS (IBS-D) may be associated with diarrhea,
  
• IBS may be a result of a bacterial infection of the GI tract,
  
• Other research suggests there may be some misdiagnosis between mild IBS and celiac disease. In celiac disease patients can not digest gluten, which is found in wheat, rye, and barley. Eating these foods, triggers an immune response that damages the small intestine.
  

Symptoms that a physician will look for include abdominal pain or discomfort for at least 12 weeks out of the previous 12 months. The pain may be relieved by a bowel movement, there may be a change in frequency of bowel movements, or in how the stool looks. There may be a feeling of uncontrollable urgency to have a bowel movement, difficulty in passing stool, mucus in the stool, and bloating. Bleeding, fever, weight loss, and persistent severe pain are not symptoms of IBS and are considered alarm features that indicate the need for further evaluation. Often, people with IBS also suffer from depression and anxiety, which can worsen symptoms. Frequently, IBS symptoms can cause depression and anxiety.

Management goals for IBS are targeted at elimination of stress and dietary triggers as well as utilizing drug therapy to help relieve the multiple symptoms of IBS. The IBS colon tends to be more responsive to even slight conflict or stress. There is some research that points to IBS being affected by the immune system. The immune system is affected by stress. So stress management, such as relaxation training and therapies, counseling and support, regular exercise, eliminating stressful situations, and adequate sleep is an important component of the IBS treatment plan.

In some patients, dietary changes may help IBS symptoms. Large meals, bloating from gas in the colon, medicines, wheat, rye, barley, chocolate, milk products, alcohol, and caffeinated drinks have been linked to worsening of IBS symptoms. Recommendations include keeping a food journal to log and isolate foods that are related to increased symptoms. If there are many foods that trigger a flare of the condition, discussing dietary changes with your physician or a dietitian may be advised. For example, many patients isolate dairy products as triggers, but because they are a major source of calcium and other nutrients such as vitamin D, patients may need add supplements to their diet to make up for the dietary loses. Other dietary changes that may help manage symptoms include increasing dietary fiber. Slowly increasing daily fiber in the diet and focusing on soluble fiber may help alleviate adverse symptoms, such as gas and bloating that can occur with increases in dietary fiber. Gas and bloating generally resolve within a couple of weeks for most patients when adding fiber to the diet. Decreasing caffeine, and decreasing the amount of air swallowed, all help with decreasing gas in the GI tract. Also eating small meals and a diet low in fat and high in carbohydrates may help.

Symptom-based management of IBS includes treatment of abdominal pain, as well as symptoms associated with IBS-D and IBS-C. Drugs used for treatment of abdominal pain include antispasmotics such as dicyclomine and hyoscyamine and tricyclic antidepressants such as amitriptyline, desimpramine, imipramine, and nortriptyline. While they have been prescribed for abdominal pain, there is little research to show that antispasmotics are any more effective than placebo. In addition, these drugs are associated with dose-related side effects such as dry mouth, constipation, urinary retention, and blurred vision. Alternatively, tricyclic antidepressants have been widely studied and when taken on a continual basis appear to be more effective than placebo at improving abdominal pain and discomfort and the symptoms of IBS-D. Patients with IBS-C may not be able to tolerate some side effects of tricyclics, such as constipation. Another type of antidepressant, the selective serotonin reuptake inhibitors (SSRIs), were studied and found to improve overall well being of patients with IBS, but were shown to be no better than placebo in impacting abdominal pain and bloating.

Treatments for diarrhea include medications to decrease intestinal transit time. Loperamide (Imodium AD) was studied and found improve stool consistency and frequency, but not to improve abdominal pain, distention, or other symptoms of IBS-D. Alonsetron (Lotronex) is approved for use in IBS-D in patients who failed conventional drug therapy. Originally approved in 2000, it was withdrawn from the market due to ischemic colitis and severe constipation. It has now been reintroduced at a lower dosage, and with a restricted prescribing program. Research on its effectiveness has shown significant improvement in stool frequency, stool consistency, abdominal pain, and global symptoms.

Constipation is sometimes managed with fiber, both soluble and insoluble to add bulk to the stool to help increase stool frequency and facilitate stool passage. Extensively studied, adding fiber to the diet has shown to have little benefit in improving stool frequency and consistency and no benefit in relieving abdominal discomfort. Osmotic laxatives, such as polyethylene glycol 3350 (Glycolax) pull water into the colon and thus increase stool transit time. At this time there have not been clinical trials evaluating their effectiveness in IBS-C. Tagaserod (Zelnorm) helps increase stool transit and alter gut hypersensitivity. Clinical studies have demonstrated that it improves stool frequency and form, abdominal pain, and symptoms associated with IBS-C. Diarrhea is a common side effect in just less than 10% of patients. Even with its positive impact on IBS symptoms, it was removed from the market in 2007 due to being linked to cardiovascular ischemic events. It is now has restricted access under an investigational new drug protocol. Lubprostone (Amitiza) is another drug that may be promising for IBS-C. It works by increasing intestinal fluid secretion and speeding stool transit. Nausea, diarrhea, and headache are the most common side effects. It is currently approved for chronic idiopathic constipation in adults. Additional clinical trials support the manufacturer filing with the FDA for a lower approved dose to be used for patients with IBS-C.

Other treatments such as probiotics and antibiotics may also provide additional relief of IBS symptoms. Probiotics have also been studied for treatment of IBS, targeting correction in a shift or imbalance in GI microflora. Probiotics are regulated as dietary supplements and therefore are not required to demonstrate efficacy. Bifidobacterium infantis and Bifidobacterium animalis are two strains that have been evaluated in clinical trials and produced improvement in IBS symptoms. Lastly, reduction in mucosal inflammation may help IBS symptoms. Antibiotics such as neomycin and rifaximin (Xifaxan), used for traveler’s diarrhea, may be beneficial in improving IBS symptoms caused by small intestine bacterial overgrowth.

At Bellevue Pharmacy, no review of a medical condition is ever complete unless the impact of hormone replacement is evaluated. In many conditions, normalization of hormones such as estradiol and progesterone will help manage and alleviate many symptoms. But in the case of IBS and hormone replacement, it is not clear if hormones worsen symptoms or if balancing hormones may actually help resolve symptoms. Gastrointestinal symptoms related to the menstrual cycle are common, but clinical trials find that IBS sufferers are more likely to report a worsening of bowel symptoms, such as stomach pain, diarrhea, nausea, and bloating during menses. Male and female sex hormones also appear to impact intestinal pain sensitivity in IBS patients. The impact of the hormones does not appear to be related to the amounts of the hormones in the body and it is unclear the impact of changes in hormones on GI symptoms. Studies show that the incidence of IBS appears to decline after the mid-forties, and then occurs with equal frequency in men and women after age 65 when hormone cease fluctuating.

Bellevue Pharmacy has a staff of consultant pharmacists available to assist you and your physician in managing your compounded hormone replacement. To schedule a consultation time with one of our pharmacists, please call 1-800-728-0288.

References:

1. Irritable Bowel Syndrome http://digestive.niddk.nih.gov/ddiseases/pubs/ibs/
   
2. Hormones and IBS http://www.med.unc.edu/ibs
   
3. Irritable Bowel Syndrome: Update on Medical Management and the Use of Probiotics http://www.uspharmacist.com/print.asp?page=ce/105597/default.htm
   
4. Irritable Bowel Syndrome http://en.wikipedia.org