Irritable bowel syndrome

1. Irritable bowel syndrome Gatroenterology Clinics of North America 32 ( 2003) : 507-529 Presented by ??? 2003.8.18

2. Epidemiology 9-22% Most prevalent digestive disease Most present before age 45, although the elderly are 92% as often as middle-aged (painful diverticular disease) Women 2-3 times than men ; 80% severe IBS Less common in Asian and Hispanics

3. Clinical Presentation The predominant symptom is abdominal pain or discomfort accompanied by a a change in stool frequency or consistency. Abdominal pain: generalized or localized, usually in the lower abdomen, relieved by defecation (or flatus passage), exacerbated by stress, food, alcohol; no progressive deterioration Altered bowel habits: the most common pattern is constipation alternating with diarrhea GI symptoms: bloating, distension, increased belching and flatulence, mucus in the stool Upper GI symptoms (25-50%): dyspepsia, heartburn, nausea and vomiting Extraintestinal symptoms: urinary frequency and urgency, sexual dysfunction, dyspareunia, menstrual difficulties, lower back pain, headaches, chronic fatigue, insomnia��tend to increase in number with the severity IBS

4. Pathophysiology GI motor abnormalities: Increased rectosigmoid motor activity Visceral sensory abnormalities: Exaggerated sensory response to visceral stimuli (visceral afferent dysfunction, visceral hyperalgesia/hypersensitivity) CNS dysfunction: Cerebral dysfunction with preferential activation of the prefrontal lobe Abnormal psychiatric feature

6. Rome II Criteria 12 or more weeks of continuous or recurrent abdominal pain or discomfort Plus at least two of the following: 1) relieved by defecation 2) associated with altered stool frequency 3) associated with altered stool form

7. Rome II Criteria Symptoms that cumulatively support the diagnosis of IBS : 1. Abnormal stool frequency ( >3 bowel movements/d or <3 bowel movements/wks) 2. Abnormal stool form (lumpy and hard or loose and watery) 3. Abnormal stool passage (straining, urgency, or feeling of incomplete evacuation) 4. Passage of mucus 5. Bloating or feeling of abdominal distension

8. Red Flags Anemia Rectal bleeding Heme-positive stools Weight loss ( >10 pounds ) Fever New or recent onset in patient older than 50 years Noctural symptoms Persistent diarrhea or severe constipation Family history of colon cancer, inflammatory bowel disease, or celiac disease Palpable abdominal or rectal mass Recent antibiotic use

9. Differential Diagnosis Epigastric or periumbilical pain : biliary tract disease, peptic ulcer disease, intestinal ischemia, carcinoma of the stomach and pancreas Lower abdomen pain : diverticular disease, inflammatory bowel disease, carcinoma of the colon Postprandial pain + bloating, nausea, vomiting : gastroparesis, partial intestinal obstruction, Giardia lamblia or other parasites Diarrhea : lactase deficiency, laxative abuse, malabsorption, hyperthyroidism, inflammatory bowel disease, infectious diarrhea Constipation : drugs( anticholinergic, antihypertensive, antidepressant), hypothyroidism, hypoparathyroidism, acute intermittent porphyria, lead poisoning

10. Treatment Pain Antispasmodics TCA & SSRI Constipation Fiber Laxatives Tegaserod (5-HT4 receptor agonist) Diarrhea Opioid agonists Cholestyramine Alosetron (5-HT3 receptor antagonist)

13. Psychologic treatments Relaxation Hypnosis, progressive muscle relaxation, biofeedback training, meditation, yoga� Cognitive-behavioral therapy Psycodynamic therapy

14. Patient Outcome Persist for more than 5 years in greater than 75% of patients Male, short history of symptoms, recent acute onset, exhibit predominantly constipation, good initial response to treatment��are most likely to achieve long-term improvement