IBS - Definition Chronic functional disorder of GI generally characterized by:
3500 3000 No. of Publications 2500 2000 1500 1000 Irritable Bowel syndrome Irritable Bowel Syndrome 500 0 1968-1977 1978-1987 1988-1997 1998-2007 Year
Challenges in IBS 1) No definitive anatomic or biochemical abnormalities 2) Incompletely understood pathogenesis 3) Absence of biochemical or structural abnormalities. 4) Diagnosis of exclusion 5) Frustration felt by both doctors and patients.
Differential Diagnosis - Exclusions GIT malignancy. Inflammatory Bowel Disease. Hypo/hyperthyroidism. Celiac Disease. Lactose intolerance. Malabsorption. GIT infections.
Local Scenario About 70% of patients GI disorders, of these, 80% are IBS. 90% of these have been investigated and treated several times for: Amobiasis Typhoid Brucellosis Peptic Ulcer Disease H. pylori eradication
Manning s s Diagnostic Criteria 1) Abdominal pain relieved with defecation. 2) Looser stools w/pain onset. 3) More frequent stools w/pain onset. 4) Abdominal distension. 5) Passage of mucus. 6) Sensation of incomplete evacuation. Manning AP, et al Towards positive diagnosis of the irritable bowel. BMJ 1978: 2: 653 4
Out-patients with IBS (%) 80 70 60 50 40 30 20 10 0 0 1 2 3 4 Number of symptoms present Manning AP, et al Towards positive diagnosis of the irritable bowel. BMJ 1978: 2: 653 4
Rome 1 Criteria for IBS 1992 At least three months continuous or recurrent symptoms of: 1) Abdominal pain and discomfort which is: a) Relieved with defecation, b) And or associated with a change in frequency of stool, c) And/or associated with a change in consistency of stool; And 2) Two or more of the following, at least a quarter of occasions or days; a) Altered stool frequency* b) Altered stool form (lumpy/hard or loose /watery stool) c) Altered stool passage (straining, urgency, or feeling of incomplete evacuation) d) Passage of mucus e) Bloating or feeling of abdominal distension. *For research purposes, altered may be defined as > 3 bowel movements /day or < 3 bowel movements per week.
Rome II Criteria for Irritable Bowel Syndrome 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: 1) Relieved with defecation; and or 2) Onset associated with a change in frequency of stool; and or 3) Onset associated with a change in form (appearance) of stool. The following symptoms cumulatively support the diagnosis of IBS. 1) Fewer than three bowel movements per week. 2) More than three bowel movements a day. 3) Hard or lumpy stools 4) Loose (mushy) or water stools 5) Straining during a bowel movement. 6) Urgency (having to rush to have a bowel movement) 7) Feeling incomplete bowel movement. 8) Passing mucus (white material ) during bowel movement. 9) Abdominal fullness, bloating and swelling. IBS subtypes: Diarrhea predominant: 1 or more of 2, 4 or 6 and none of 1, 3 or 5 Constipation predominant: 1 or more of 1, 3 or 5 and none of 2, 4 or 6
The Bristol Stool Form Scale
Rome III Criteria* Irritable Bowel Syndrome Recurrent abdominal pain or discomfort at least 3 days/month in the last 3 months associated with 2 or more: Improvement with defecation and Onset associated with a change in frequency of stool and Onset associated with a change in form (appearance) of stool *Criteria fulfilled for the last 3 months with symptom onset at least 6 months prior to diagnosis. Longstreth G., Gastroenterology 2006
There are four groups of symptoms Abdominal pain / discomfort. Bloating / abdominal distension. Defecatory symptoms Non-intestinal symptoms The first three are represented in the Manning criteria, which are practical and simple to use.
Non-Intestinal Symptoms Upper Gut symptoms Excessive fullness after meals Nausea Odynophagia (less common) Urinary symptoms Urgency Frequency Feeling of incomplete emptying Dyspareunia Fatigue Muscular aches and tenderness Backache & headache
These are: Fever Anaemia. Alarm symptoms Unexplained weight loss. Blood in stools Persistent diarrhea or constipation. New onset symptoms. Family history of GI malignancy, Inflammatory Bowel disease.
Performance of Symptom Based Criteria Manning Criteria - positive predictive value 65 75% Rome Criteria/absence of alarm features - Sensitivity 65% - Specificity 100% - Positive predictive value 98 100% - Negative predictive value 76% Rome II less sensitive than Rome I - In known IBS, Rome I identified 83% and Rome II 49% (P < 0.001) - Rome Criteria underestimate prevalent IBS Vaneer et al AJG 1999
Prevalence of Organic Disease Organic disease IBD Cancer Celiac disease Thyroid disease Lactase Def. IBS 0.51 0.98 % 0 0.51 % 4 5% 6% 22-26 % General population 0.3 1.2 % 0 0.6% 0.25 0.5 % 5-99 % 25% Digestion 2004; 70: 207-209
What lab tests then? Are counterproductive create anxiety. raise doubt in the patients mind on the functional diagnosis. can cause misdiagnosis à incorrect / dangerous treatments. Absolute indications any alarm symptom Relative indications e.g. short history, atypical history e.g. pains unrelated to defecation, old age at onset.
Symptom Based Criteria ( Road( to Rarely used Confidently diagnose IBS Avoid unnecessary exposure to harmful tests & treatments. Rome )
Epidemiology Overall prevalence approximately 9-22% Vary widely in different populations. Females : Males 2:1 Responsible for approximately 40% referrals to gastroenterologists. Not a life threatening disease but has a dramatic effect on the quality of life (HRQOL)
Pathophysiology 1) Abnormal motility. 2) Visceral hypersensitivity. 3) Dysfunction in the enteric nervous system (ENS) With neurotransmitters predominantly serotonin (5HT3 / 5HT4). Acts as agonist and antagonists. 4) Gut Brain axis.
GUT-BRAIN AXIS
Pathophysiology Abnormal motility 1950 Visceral hypersensitivity Brain gut interaction 5-HT mediated visceral (ENS) Sensitivity and gut motility. ty. Evolution of mechanistic hypothesis of IBS
? Other pathogenetic mechanisms Post-infectious IBS Small intestinal bacterial overgrowth (SIBO)
Pathophysiology of IBS Gas retention Psychosocial factors low grade inflammation From food hypersensitivity Prior gastroenteritis Altered motility Altered sensation
Management Real challenge. No single drug to treat all symptoms. R x still symptomatic. New drugs development.
Management approach General approach R x based on pre-dominant symptoms R x Based on severity of symptoms
Difficulties caused by the inconveniences of IBS Abdominal pain Limited social life Abdominal bloating or distention Inability to travel Flatulence Dietary restrictions Abdominal discomfort Unexpected onset of symptoms Constipation Embarrassment Diarrhea Sleep disturbance Frequent and explosive motions Lack of energy Depression Nausea Embarrassingly noisy intestines Interruptions at work Lethargy Mental anguish Inability to concentrate Calculated from analysis of 907 questionnaires. International Journal of Gastroenterology; March 1998
Continuum of the severity in IBS MILD MODERATE SEVERE Estimated prevalence 60% 85% 15% Clinical setting Primary Secondary Tertiary Physiologic Correlation +++ ++ + Symptom Constancy 0 + +++ Activity Disruption 0 + +++ Health care use + ++ +++ Illness Behavior 0 + +++ Psychiatric Diagnoses 0 + +++
Mild Symptoms. Positive diagnosis Explain, reassure Diet Lifestyle advise
Moderate to severe symptoms Same as mild a) Pain i. Smooth muscle relaxant Otilonium. ii. Anti-spasmodic Mebeverine. iii. Small dose tricyclic anti-depressant. b) Diarhoea i. Loperamide. ii. Cholestyramine. iii. 5HT3 agonist - Alosetron. c) Constipation i. Fiber Fybogel, Senokot, ii. Osmotic agents. iii. 5HT4 antagonist - Tegaserod.
Antibiotics / Probiotics for IBS Reasons for symptom improvement unclear Optimal diagnostic test for SIBO unclear Optimal antibiotic therapy unclear Benefits appear transient Potential consequences of repeated, widespread anti-biotic use? Non-absorbable Rifaximin. Probiotics for bloating.
In Santa Barbara 1933 Life is like riding a bicycle, to keep your balance, you must keep moving. - Albert Einstein, in a letter to his son, Eduard, February 5, 1930.