Functional gastrointestinal (GI) and motility disorders are collectively the most common GI conditions diagnosed by gastroenterologists (physicians specializing in GI diseases) and primary care physicians. These conditions include irritable bowel syndrome (IBS), chronic constipation, chronic diarrhea, atypical chest pain, and fecal incontinence. Functional GI disorders have a worldwide prevalence and affect up to 20% of the population. In the US alone, 30 to 60 million people suffer from functional GI disorders. The word “functional” refers to the fact that these conditions cannot (yet) be reliably diagnosed using blood tests, imaging studies, tissue samples, or other forms of objective biological evidence; that is, they cannot be easily explained by anatomic or structural abnormalities. Instead, these conditions are principally diagnosed by relying on the patient report of their symptoms, and by ruling out other conditions that might mimic the symptoms.

What conditions comprise functional GI disorders?

Functional GI disorders are chronic or recurring medical conditions that can affect any part of the entire GI tract from the esophagus to the colon. Functional GI Diseases are comprised of a number of GI diseases including functional or atypical chest pain, irritable bowel syndrome (IBS), functional dyspepsia, chronic constipation, gastroesophageal reflux disease (GERD) and fecal incontinence.

How common are functional GI disorders?

IBS alone accounts for 12% of all diagnoses in primary care practices, and Functional GI Diseases as a group account for over 40% of diagnoses made by gastroenterologists in their clinical practices.

What are the symptoms of functional GI disorders?

In these conditions, the stomach and bowel may not function normally and causes symptoms that can range from heartburn, difficulty swallowing food, nausea and vomiting, abdominal pain, bloating, gas, diarrhea and constipation. Often these symptoms are so severe as to cause disruption to the quality of life of the patient.

Who suffers from these GI diseases?

Functional GI disorders affect children, adults, women and men – everyone can be affected, although the conditions occur three times more often in women. Doctors frequently have difficulty distinguishing these diseases from other GI diseases such as celiac disease and inflammatory bowel disease, such as Crohn’s disease and ulcerative colitis, and also gynecologic conditions such as endometriosis, ovarian cancer and chronic pelvic pain; this further complicates making a definitive diagnosis. Symptoms intensify during the menstrual cycle and during the peri-menopausal period. Children and young adults affected by these conditions often suffer their entire lives with pain and discomfort.

How do these GI diseases affect a person’s life?

Functional GI disorders can seriously impair the quality of life and daily functioning of patients. These diseases have a comparable quality of life as diabetes, end-stage kidney failure and depression. Despite advances in modern medicine, it remains extremely rare to achieve a full cure in patients with these conditions.

In addition to affecting quality of life, the functional GI disorders can also diminish productivity on the job. As a group, these disease cost society untold billions of dollars in opportunity costs from lost or diminished work. Adults report 10-14 hours of lost work productivity per week and 3-4% work time missed. Many patients report that their daily functioning, social activities and personal relationships are severely impacted by their conditions. We found that patients report an average decrease in quality of life of 25%. In addition, affected children frequently miss school due to their symptoms.

What are the possible causes of these GI diseases?

Some research indicates that patients with Functional GI disorders have increased sensitivity of their bowels. Research also shows that these patients may have disturbances in the communication pathways between the brain and bowel; this can result in abnormal bowel function. Disturbances in any part of these communication pathways and networks can cause lead to GI disease and symptoms.

Although the cause of Functional GI disorders like IBS is not completely understood, we have been able to establish risk factors for these conditions. For example, we now know these conditions can be hereditary, and that certain genes can predispose a person to get them. Also, traumatic events early in life (e.g., abuse) can increase the vulnerability of an individual to get these conditions. Studies also indicate that chronic stress and/or intestinal infections (e.g., food poisoning) can trigger the onset of symptoms.

How are these GI diseases diagnosed?

There are currently no definitive tests that can diagnose these diseases. They are diagnosed by patient symptoms, but unfortunately, many other diseases can cause similar symptoms. This makes the diagnosis uncertain at best. For example, IBS is characterized by abdominal pain and diarrhea, but patients with colon cancer, Crohn’s disease, colitis, and celiac disease also report these same symptoms.

Many people with these diseases do not seek health care because they do not think doctors can help them. When patients do seek medical attention, the diagnosis takes 3 years on average, and patients see 3 doctors before a proper diagnosis is made.

What is the treatment for functional GI disorders?

Treatment has multiple components that include education about the medical condition, diet and lifestyle changes, medications (over the counter remedies and prescription), behavioral treatments (hypnosis, cognitive behavioral therapy, mindfulness meditation, etc). Treatment is normally based on a patient’s symptoms, particularly those that are most bothersome.

  • Diet: Studies have shown that dietary modification can be helpful in reducing symptoms for GERD (gastroesophageal reflux disease), irritable bowel syndrome (IBS), chronic constipation, chronic diarrhea, gastroparesis, and gas and bloating. The Digestive Health and Nutrition Clinic at UCLA has an experienced dietitian knowledgeable in the assessment and treatment of GI conditions.
  • Constipation: Fiber supplementation, over the counter remedies such as laxatives (polyethylene glycol 3350 [MiralaxÒ], senna, and bisacodyl) can be helpful in managing symptoms. If prolonged treatment is needed, patients should consult their physician. FDA approved medications for the treatment of chronic constipation and IBS with constipation include Lubriprostone (AmitizaÒ) and Linaclotide (LinzessÒ).
  • Diarrhea: In addition to diet, medications can reduce diarrhea. Loperamide (ImodiumÒ) is an anti-diarrhea medication that is available over the counter and can reduce diarrhea. There are also prescription medications that have been to improve diarrhea and they include Diphenoxylate (LomotilÒ), antibiotics and Alosetron (LotronexÒ), but the use of these medications should be discussed with your physician.
  • Bloating and gas: Diet and probiotics have been shown to reduce bloating and gas in some patients. In patients with IBS with diarrhea, antibiotics can improve bloating symptoms. In patients with IBS with constipation, Lubriprostone (AmitizaÒ) and Linaclotide (LinzessÒ) have been shown to be effective in reducing bloating symptoms.
  • Abdominal pain: The cause of abdominal pain needs to be determined under the physician’s guidance. Mild or intermittent abdominal pain associated with IBS can be treated with medications such as anti-spasmodics (LevsinÒ, BentylÒ, and DonnatolÒ) Chronic or more severe abdominal pain is often treated with antidepressants which affect pain pathways in the body to reduce pain. Abdominal pain associated with IBS can also be effectively treated with therapies listed above.
  • Behavioral therapies: These treatments help reduce abdominal symptoms and distress associated with these symptoms. They also improve a patient’s ability to manage symptoms. These therapies are tolerated well and are not associated with any harmful effects. These treatments include
    • Cognitive-behavioral treatment.
    • Hypnosis
    • Stress management
    • Mindfulness Meditation
    • Other relaxation methods
  • Biofeedback: Anal sphincter and pelvic floor muscles may not be coordinated or function properly in chronic constipation and fecal incontinence. In the case of chronic constipation, some patients have dyssynergic defecation (also known as anismus), where the pelvic floor and anal sphincter muscles and abdominal wall muscles are not coordinated properly to allow normal stool passage. In fecal incontinence, the anal sphincter muscles may be weak so stool leakage occurs. Anorectal biofeedback is a treatment that helps retrain the pelvic floor muscles and anal sphincter muscles. Clinical studies have shown that biofeedback to be effective in treating chronic constipation due to dyssynergic defecation and fecal incontinence.
 
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