Irritable bowel syndrome
Gatroenterology Clinics of North America
32 ( 2003) : 507-529
Presented by 高毓佳
2003.8.18
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
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
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
Diagnostic Testing
• CBC
• Serum e-
• ESR
• TSH
• Stool routine
50 y/o : colonoscopy or air-contrast barium enema
PES or UGI series
Ultrasound
Severe or persistent Diarrhea
• Malabsorption screen (fecal fat, serum B12 , red cell folate, plasma ferritin,
serologic tests for celiac sprue)
• Stool cultures, Clostridium difficile toxin, ova and parasites
• Lactose tolerance test : Hydrogen breath test or lactose-free diet for 3 wks
Constipation , severe rectal urgency or fecal incontinence
• Colonic transit study
• Anorectal function tests (e.g., manometry and electrophysiology)
• Endoanal ultrasonography
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
Rome II Criteria
Symptoms that cumulatively support the diagnosis of
IBS :
1. Abnormal stool frequency ( >3 bowel
movements/d or 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
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
Treatment
• Pain
– Antispasmodics
– TCA & SSRI
• Constipation
– Fiber
– Laxatives
– Tegaserod (5-HT4 receptor agonist)
• Diarrhea
– Opioid agonists
– Cholestyramine
– Alosetron (5-HT3 receptor antagonist)
Increase motor activity or promote propulsion
Dopamine receptor antagonists—Metochlpromide (Primperan)
Serotonin 5-HT4 receptor agonists
Cisapride (prepulsid)
Tegaserod
Somatostatin analogue
Inhibit motor activity or slow propulsion
Antispasmotic drugs
Anticholinergic drugs—Dicyclomine (Bentyl)
Calcium channel antagonists—Diltiazem (Herbesser)
Opiate antidiarrheal agents—Loperamide (Imodium)
Somatostatin analogue
Serotonin 5-HT1 receptor agonists—Sumatriptan (Imigran), Busirone (Buspar)
Blunt visceral sensation
Antidepressant agents
Tricyclic antidepressant
Selective serotonin reuptake inhibitors—Fluoxetine (Prozac), Sertraline (Zoloft)
Serotonin 5-HT3 receptor antagonists—Granisetron (Kytril), Ondonsetron (Zofran)
Opiate analogues
Somatostatin analogues
Psychologic treatments
• Relaxation
– Hypnosis, progressive muscle relaxation,
biofeedback training, meditation, yoga…
• Cognitive-behavioral therapy
• Psycodynamic therapy
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