Irritable bowel syndrome

Irritable bowel syndrome (IBS), also sometimes referred to as spastic colon, is a fairly common functional abdominal condition featuring abdominal pain and changes in bowel habit. Up to 50% of visits to specialists of gastroenterology are due to this condition.

Table of contents

1 Diagnosis 2 Etiology 3 Rome II criteria 4 Treatment 5 See also 6 External links

Diagnosis

According to Rome II criteria (see below) it can be diagnosed when abdominal pain or discomfort goes along with changes in stool pattern. Many patients with symptoms of IBS do not suffer from IBS but from lactose intolerance or fructose malabsorption. In a fair proportion of these cases, symptoms disappear under an appropriate diet. Some physicians do not believe IBS is a genuine identifiable syndrome. One gastroenterologist stated, "the intestinal nervous system is not well understood. IBS is a trash can we use for everything we don't understand."

Etiology

Research on the etiology of IBS has not yet brought forth unanimous results. Changes in colonic motility and immunologic causes have been discussed. Hypersensitivity of the gut is a major finding in IBS patients. The association of IBS with stress is less clear.

About 25% of patients develop symptoms after a hefty enteritis (partially after use of antibiotics, see also diarrhea). About 50% of women with IBS report a history of sexual or physical abuse.

Therefore, some believe that IBS really is a conglomeration of disorders with similar symptoms but a different etiology. On the other hand, some alternative medical practitioners theorize that IBS is solely caused by antibiotics and treat the syndrome with diet and probiotics.

Rome II criteria

According to the Rome II consensus conference of the American Gastroenterological Association and international medical societies on functional bowel disorders, the diagnosis of IBS can be made when the following criteria are fulfilled:

At least 12 weeks, which need not be consecutive, in the preceding 12 months of abdominal discomfort or pain that has 2 of 3 features:

• Relieved with defecation; and/or
• Onset associated with a change in frequency of stool; and/or
• Onset associated with a change in form (appearance) of stool.

Symptoms that cumulatively support the diagnosis of IBS

• Abnormal stool frequency (for research purposes, “abnormal” may be defined as greater than 3 bowel movements per day and less than 3 bowel movements per week);
• Abnormal stool form (lumpy/hard or loose/watery stool);
• Abnormal stool passage (straining, urgency, or feeling of incomplete evacuation);
• Passage of mucus;
• Bloating or feeling of abdominal distention.

The diagnosis of a functional bowel disorder always presumes the absence of a structural or biochemical explanation for the symptoms. (Source: AGA.)

Exclusion of structural disorders via:

• colonoscopy
• esophagogastroduodenoscopy (EGD)
• abdominal ultrasound
• blood tests: full blood count, liver enzymes, electrolytes, renal function
• stool chemistry (e.g. tests for exocrine pancreas insufficiency and other malabsorption conditions), stool microbiology, fecal fat
• H₂-tests for lactose intolerance and fructose malabsorption
• deep duodenal biopsy or blood tests for celiac disease, an autoimmune response to the gluten found in wheat, rye, and barley.

Evaluation of sensory thresholds via a barostat is currently under discussion as a diagnostic test, however sensitivity and specificity of this test are not yet high enough to allow a wide clinical use.

Treatment

Dependent on symptoms, treatment can consist of stool softeners and laxatives, antidiarrheals (loperamide) and analgesics. Alosetron, a modern drug that initially showed some promising results, is only moderately successful in the management of diarrhea-predominant IBS. Tegaserod maleate (Zelnorm) was recently approved in the U.S. for women with constipation-predominant IBS, but has been shown to be only moderately more effective than placebo in controlling symptoms. Many patients benefit from psychotherapy, however many others refuse to undertake one.

See also

• chronic functional abdominal pain
• lactose intolerance
• fructose malabsorption
• Crohn's disease
• ulcerative colitis

External links

• American College of Gastroenterologists IBS Resource Center
• IBS Self Help and Support Group
• Health A to Z Irritable Bowel Syndrome article
• Health A to Z Digestive Disorders - IBS article

Health science - Medicine - Gastroenterology

Diseases of the esophagus - stomach

Halitosis - Nausea - Vomiting - GERD - Achalasia - Esophageal cancer; - Esophageal varices; - Peptic ulcer; - Abdominal pain; - Stomach cancer - functional dyspepsia;

Diseases of the liver - pancreas - gallbladder - biliary tree

Hepatitis - Cirrhosis - NASH - Budd-Chiari syndrome; - Hepatocellular carcinoma; - Pancreatitis - Pancreatic cancer - Gallstones - Cholecystitis

Diseases of the small intestine

Peptic ulcer; - Malabsorption (e.g. celiac disease;, lactose intolerance;, fructose malabsorption;, Whipple's disease;) - Lymphoma

Diseases of the colon

Diarrhea - Appendicitis - Diverticulitis - Diverticulosis - IBD (Crohn's disease; and Ulcerative colitis;) - Irritable bowel syndrome - Constipation - Colorectal cancer - Hirschsprung's disease; - Pseudomembranous colitis;