Continuing EducationHomestudyNutrition

Irritable Bowel Syndrome (IBS)

ibsBy Dr. Mary O’Brien MD

Gastrointestinal (GI) disorders are common in the U.S. and throughout the world and cause considerable morbidity, reduced quality of life, and, in some cases, mortality, while exacting a heavy economic toll. At the present time, it is estimated that GI disorders affect more than one in five Americans, particularly women.

IBS (irritable bowel syndrome) is one of the most common bowel disorders. It is characterized by chronic or recurring symptoms of lower abdominal pain, changes in bowel habits (diarrhea, constipation, or both), a feeling of incomplete rectal emptying, passage of mucus with stools, and abdominal bloating and distention.

Abdominal pain or discomfort in association with bowel dysfunction is the primary symptom of IBS. Additional symptoms vary from person to person. Some people have constipation; others have diarrhea along with an urgent need to move the bowels; and still others have alternating constipation and diarrhea. Some people experience bloating or abdominal distension, tenesmus (straining but inability to complete defecation, frequently painful), or pass mucus with their bowel movement. Several extra-intestinal symptoms may also be present in IBS. These include depression, anxiety, fibromyalgia, chronic fatigue syndrome, temporal mandibular joint disorder, and chronic pelvic pain. In addition, asthma and headache may occur.

Research suggests that many patients with IBS have abnormal GI motility, unusual sensitivity to stretching or fullness in the intestines, and heightened amplification of pain signals in the brain. IBS may be triggered by numerous factors, including bacterial gastroenteritis, physical or sexual abuse, small intestinal bacterial overgrowth, and abnormal levels of neurotransmitters and hormones.

Bleeding, fever, weight loss, anorexia, persistent severe pain, and nocturnal diarrhea are not symptoms of IBS and may indicate other problems such as infection, ulcerative colitis, Crohn’s disease, or cancer. Gastrointestinal disorders are common and can cause considerable suffering, compromised quality of life, and even fatal complications. An understanding of the pathophysiology and clinical features of the more common GI conditions can assist clinicians in diagnosing these disorders accurately. Management of symptoms with medications often depends on whether the dominant symptom is diarrhea or constipation. Extensive and ongoing research is helping to pinpoint the causes of these disorders and to guide clinicians in safe and effective approaches to treatment.