Irritable bowel syndrome

irritable bowel syndrome - general medicine

1. IRRITABLE BOWEL SYNDROME IBS RAHNA 66

2. DEFINITION EPIDEMOLOGY ETIOPATHOGENESIS CLINICAL FEATURES DIAGNOSIS RED FLAG SIGNS INVESTIGATIONS TREATMENT

3. Definition It is a functional bowel disorder characterized by abdominal pain or discomfort and altered bowel movements in the absence of detectable structural abnormalities Chronic, recurrent ,relapsing and often lifelong Often overlap with other functional disorders like fibromyalgia, headache, backache and genitourinary symptoms

4. epidemiology Prevalence : 1-20% worldwide (10% to 20% - US and Europe 5% - Asian countries) Incidence : 1-2% per year 2-3 times more common in women M ost patients have their first symptoms before 45 years of age INDIA Prevalence is 4-8% More common in men

5. ETIOpathogenesis Etiology is uncertain and maybe multifactorial Pathogenesis in IBS is poorly understood GI Motor Abnormalities Visceral Hypersensitivity Brain gut axis Dysregulation Abnormal Psychological features

6. Postinfectious IBS Risk factors- young females,prololged duration of initial illness, toxicity of infecting bacterial strain Microbes involved in initial infection – Campylobacter ,salmonella and shigella Immune activation and low grade mucosal inflammation Altered gut flora Abnormal serotonin pathways Serotonin plays an important role in regulation of GI motility and visceral perception IBS –D patients show increased 5HT containing enterochromaffin cells in colon

7. Clinical features Abdominal pain and discomfort Altered bowel habits Gas and flatulence Upper GI symptoms

8. Abdominal pain or discomfort A prerequisite for the diagnosis of IBS It is episodic and crampy & highly variable in intensity and location Sleep deprivation and malnutrition is uncommon Pain exacerbated by eating and emotional stress and improved by passing stools or flatus In females symptoms worsen during premenstrual and menstrual phases

9. Altered bowel habits - Alteration in bowel habits most consistent clinical feature Most common pattern is constipation alternating with diarrhea At first constipation is episodic but later becomes continuous and unresponsive to laxatives Stools are usually hard with narrowed caliber Sense of incomplete evacuation Pts. with diarrhea have a stool volume <200ml and maybe associated with passage of mucus but not blood Nocturnal diarrhea not seen

10. Gas and flatulence - Pts complain of abdominal distention and increased belching or flatulence Upper GI symptoms - 25-50% complain of dyspepsia, heartburn, nausea and vomiting Indian patients have more of upper GI symptoms

11. Types IBS-D (Diarrhoea predominant) IBS-C (Constipation predominant) IBS-M (Mixed diarrhoea and constipation) Usefulness of subtypes debatable Within 1 yr 75% change subtypes & 29% switch between IBS-C and IBS-D

12. Diagnosis No clear diagnostic markers exist for IBS So diagnosis depends on positive clinical features and ruling out organic diseases by careful clinical examination and investigations Diagnosis can be made confidently in most patients u sing Rome III criteria + absence of red flag signs + supportive symptoms w hich include defecation straining, urgency or a feeling of incomplete bowel movement ,passing mucus and bloating

13. Sensitivity 17% Specificity 95%

14. Red flag signs & symptoms Unintentional and unexplained wt. loss Rectal bleeding F amily h/o bowel/ovarian cancer A change in bowel habit to loose and/or more frequent stools persisting for more than 6 wks in a person aged over 60yrs. Anemia Abdominal masses Rectal masses Inflammatory markers for IBD

15. investigations To rule out organic causes CBC ESR CRP Stool examination for ova and parasites Antibodies for Coeliac Disease Hydrogen breath test Sigmoidoscopy when more than 50 years/ red flag signs present Younger individual with mild symptoms – minimal diagnostic evaluation, Older – undergo more thorough evaluations

16. Differential diagnosis IBD COLORECTAL CANCER COLONIC TB FRUCTOS/LACTOSE INTOLERENCE’ CELIAC SPRUE Endocrinopathies - HYPOTHYROIDISM ,HYPERTHYROIDUSM INFECTIOUS COLITIS ACUTE INTERMITTENT PORPHYRIA and LEAD POISONING PHYCOLOGICAL –ANXIETY,DEPRESSION

17. treatment Patient education and counselling Dietary alteration Pharmacotherapy Psychotherapy

18. Patient COUNSELLING Reassuring the patient is the most successful form of treatment for IBS Many are concerned that they have developed cancer – more anxiety -more colonic symptoms Explain functional nature of disorder and how to avoid obvious food precipitants Emphasise on expected chronicity of symptoms with periodic exacerbations

19. Diet Modification Eliminate food stuffs that appear to produce symptoms Consume high fibre diet – IBS-C Exclude wheat ,diary and gluten –Pain and bloating Avoid legumes and excess dietary fibre - IBS-D Diet low in FODMAPs ( F ermentable O ligosaccharides, D isaccharides, M onosaccharides A nd P olyols) FODMAPs areshort chain carbs poorly absorbed in small intestine and fermented by bacteria in colon to produce gas

20. DRUGS Antidiarrheal agents Delay faecal transit , increase colonic segmentaion contractions and reduce rectal perception Serotonin receptor agonist and antagonist 5 HT3 receptor agonist – 5 HT release increases secretions and reduces GI transit time and cause constipation and hence useful in IBS-D. Eg :- Alosetron s/e- Causes ischemic colitis and severe constipation 5 HT4 agonist – are prokinetic eg Tegaserod - Suspended due to CVS events.

21. Stool bulking agents Fibre speeds up colonic transit and prevent excessive hydration and dehydration of stool Chloride channel activators Chloride secretion induce passive movement of Na and water into bowel lumen and improve bowel function Guanylate Cyclase-C Agonist Activation of GC-C generates cGMP which triggers secretion of fluid , sodium and bicarbonate

22. Antidepressant drugs TCAs reduce visceral hypersensitivity Their antimuscarinic effects cause constipation. Useful in IBS-D SSRIs are secretagogues and stimulate GI motility. Helpful in IBS-C Modulation of gut flora- Rifamixin , probiotics Antispasmodics provide temporary relief for painful cramps related to intestinal spasm Inhibit gastrocolic reflux and reduce postprandial pain s/e –xerostomia, urinary retention ,blurred vision ,drowsiness

23. Psychological therapy Psychological therapy is effective in two thirds of patients with IBS who do not respond to standard medical treatment Cognitive behavioral therapy Hypnotherapy Dynamic therapy

24. To conclude   Chronic relapsing condition with considerable financial burden and impacts overall quality of life At present only symptomatic therapy available Drugs don’t alter the clinical course Treatment should be tailored to the individual patient and should be a combination of therapies No serious complications Haemorrhoids - aggravated by constipation and diarrhoea Vitamin and mineral deficiencies – because of avoiding certain food s

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