Published on October 30, 2007
Irritable Bowel Syndrome: Irritable Bowel Syndrome Dr Bruce Davies Introduction: Introduction First described in 1771. 50% of patients present <35 years old. 70% of sufferers are symptom free after 5 years. GPs will diagnose one new case per week. GPs will see 4-5 patients a week with IBS. Point prevalence of 40-50 patients per 2000 patients. What Is IBS?: What Is IBS? A syndrome. One man’s constipation is another man’s normality. Cause unknown. 20% seem to start after an episode of gastroenteritis. Diagnostic Criteria: Diagnostic Criteria Rome 11 Diagnostic criteria. Manning’s Criteria. Rome 11 Diagnostic Criteria.: Rome 11 Diagnostic Criteria. At least 12 weeks history, which need not be consecutive in the last 12 months of abdominal discomfort or pain that has 2 or more of the following: Relieved by defecation. Onset associated with change in stool frequency. Onset associated with change in form of the stool. Rome 11 Diagnostic Criteria.: Rome 11 Diagnostic Criteria. Supportive symptoms. Constipation predominant: one or more of: BO less than 3 times a week. Hard or lumpy stools. Straining during a bowel movement. Diarrhoea predominant: one or more of: More than 3 bowel movements per day. Loose [mushy] or watery stools. Urgency. Rome 11 Diagnostic Criteria.: Rome 11 Diagnostic Criteria. General: Feeling of incomplete evacuation. Passing mucus per rectum. Abdominal fullness, bloating or swelling. Manning’s Criteria.: Manning’s Criteria. Three or more features should have been present for at least 6 months: Pain relieved by defecation. Pain onset associated with more frequent stools. Looser stools with pain onset. Abdominal distension. Mucus in the stool. A feeling of incomplete evacuation after defecation. Associated Symptoms: Associated Symptoms In people with IBS in hospital OPD. 25% have depression. 25% have anxiety. Patients with IBS symptoms who do not consult doctors [population surveys] have identical psychological health to general population. In one study 70% of women IBS sufferers have dyspareunia. Associated Symptoms: Associated Symptoms Stressful life events are associated. Compared with controls people with IBS are less well educated and have poorer general health. Women:Men = 3:1. Reasons to Refer: Reasons to Refer Age > 45 years at onset. Family history of bowel cancer. Failure of primary care management. Uncertainty of diagnosis. Abnormality on examination or investigation. Urgent Referral: Urgent Referral Constant abdominal pain. Constant diarrhoea. Constant distension. Rectal bleeding. Weight loss or malaise. Subtypes: Subtypes Diarrhoea predominant. Constipation predominant. Pain predominant. Differential Diagnosis: Differential Diagnosis Inflammatory bowel disease. Cancer. Diverticulosis. Endometriosis. A positive diagnosis, based on Manning’s criteria may provoke less anxiety than extensive tests. Examination: Examination Results should be normal or non-specific. Abdomen and rectal examination. FBC, CRP. No consensus as to whether FOBs or sigmoidoscopy is needed. Treatment: Treatment Patients’ concerns. Explanation. Treatment approaches. Patients’ Concerns.: Patients’ Concerns. Usually very concerned about a serious cause for their symptoms. Take time to explore the patients agenda. Remember that investigations may heighten anxiety. Explanation.: Explanation. Must offer a plausible reason for symptoms. Even if cause is unknown, patients require some explanation. Drawing a parallel with baby colic may help. Stress is currently a socially acceptable explanation for many symptoms in life. Treatment Approaches.: Treatment Approaches. Placebo effect of up to 70% in all IBS treatments. Treatment should depend on symptom sub-type. Often considerable overlap between sub-groups. Antidepressants: Antidepressants Poor evidence for efficacy. Better evidence for tricyclics. Very little evidence for SSRIs. Diarrhoea Predominant.: Diarrhoea Predominant. Increasing dietary fibre is sensible advice. Fibre varies, 55% of patients will get worse with bran. “Medical fibre” adds to placebo effect. Loperamide may help. Constipation Predominant.: Constipation Predominant. Increased fibre. Osmotic laxatives helpful. Ispaghula husk is one. Stimulant laxatives make symptoms worse. Lactulose may aggravate distension and flatulence. Pain Predominant.: Pain Predominant. Antispasmodics will help 66%. Mebeverine is probably first choice. Hyoscine 10mg qid can be added. Bloating may be helped by peppermint oil. Nausea may require metoclopramide. Diet: Diet Dietary manipulation may help. Food intolerance is common food allergy is rare. Relaxation therapies may be useful adjunct. Referral: Referral About 15% of patients seen by GPs with IBS are referred. Gastroenterology – Mainly upper GI symptoms. General Surgical – Lower GI symptoms. Self-help: Self-help IBS network, St John’s House, Hither Green Hospital, Hither Green Lane, London SE13 6RU Audit?: Audit? Numbers on repeat prescription for anti-spasmodics. Do they use their drugs as prescribed? What other medications do they use? Referral rates? What investigations are done? Protocol? Formulary? Psychological Thoughts: Psychological Thoughts Should a mental health assessment always be done? Should all therapy be directed at psychological causes? Is IBS a physical or a somatisation disorder?