Diagnosis and management of irritable bowel syndrome in primary care

National Institute for Health and Clinical Excellence

Key priorities for implementation

• Healthcare professionals should consider assessment for (irritable bowel syndrome) IBS if the person reports having had any of the following symptoms for at least 6 months:
  • Abdominal pain or discomfort
  • Bloating
  • Change in bowel habit
• All people presenting with possible IBS symptoms should be asked if they have any of the following ‘red flag’ indicators and should be referred to secondary care for further investigation if any are present:
  • unintentional and unexplained weight loss
  • rectal bleeding
  • a family history of bowel or ovarian cancer
  • a change in bowel habit to looser and/or more frequent stools persisting for more than 6 weeks in a person aged over 60 years
• All people presenting with possible IBS symptoms should be assessed and clinically examined for the following ‘red flag’ indicators and should be referred to secondary care for further investigation if any are present
  • anaemia
  • abdominal masses
  • rectal masses
  • inflammatory markers for inflammatory bowel disease
• If there is significant concern that symptoms may suggest ovarian cancer, a pelvic examination should also be considered
• A diagnosis of IBS should be considered only if the person has abdominal pain or discomfort that is either relieved by defaecation or associated with altered bowel frequency or stool form. This should be accompanied by at least two of the following four symptoms:
  • altered stool passage (straining, urgency, incomplete evacuation)
  • abdominal bloating (more common in women than men), distension, tension or hardness
  • symptoms made worse by eating
  • passage of mucus

• Other features such as lethargy, nausea, backache and bladder symptoms are common in people with IBS, and may be used to support the diagnosis

• In people who meet the IBS diagnostic criteria, the following tests should be undertaken to exclude other diagnoses:
  • full blood count (FBC)
  • erythrocyte sedimentation rate (ESR) or plasma viscosity
  • c-reactive protein (CRP)
  • antibody testing for coeliac disease (endomysial antibodies [EMA] or tissue transglutaminase [TTG])
• The following tests are not necessary to confirm diagnosis in people who meet the IBS diagnostic criteria:
• ultrasound
• rigid/flexible sigmoidoscopy
• colonoscopy; barium enema
• thyroid function test
• faecal ova and parasite test
• faecal occult blood
• hydrogen breath test (for lactose intolerance and bacterial overgrowth)
• People with IBS should be given information that explains the importance of self-help in effectively managing their IBS. This should include information on general lifestyle, physical activity, diet and symptom-targeted medication
• Healthcare professionals should review the fibre intake of people with IBS, adjusting (usually reducing) it while monitoring the effect on symptoms. People with IBS should be discouraged from eating insoluble fibre (for example, bran). If an increase in dietary fibre is advised, it should be soluble fibre such as ispaghula powder or foods high in soluble fibre (for example, oats)
• People with IBS should be advised how to adjust their doses of laxative or antimotility agent according to the clinical response. The dose should be titrated according to stool consistency, with the aim of achieving a soft, well-formed stool (corresponding to Bristol Stool Form Scale type 4)
• Healthcare professionals should consider tricyclic antidepressants (TCAs) as second-line treatment for people with IBS if laxatives, loperamide or antispasmodics have not helped. TCAs are primarily used for treatment of depression but are only recommended here for their analgesic effect
• Treatment should be started at a low dose (5–10 mg equivalent of amitriptyline), which should be taken once at night and reviewed regularly. The dose may be increased, but does not usually need to exceed 30 mg*

*At the time of publication (February 2008) TCAs did not have UK marketing authorisation for the indication described. Informed consent should be obtained and documented

full guideline available from…
National Institute for Health and Clinical Excellence, MidCity Place, 71 High Holborn, London WC1V 6NA
guidance.nice.org.uk/CG61

National Institute for Health and Clinical Excellence. Diagnosis and management of irritable bowel syndrome in primary care. Quick Reference Guide. February 2008