Quality statement 2: Giving a diagnosis

Quality statement

Adults with symptoms of irritable bowel syndrome are given a positive diagnosis if no red flag indicators are present and investigations identify no other cause of symptoms.

Rationale

Irritable bowel syndrome can be difficult to diagnose, and it is important to reach the correct diagnosis while striking the right balance between too few and too many investigations. Under‑diagnosis and over‑investigation can prevent effective management. When red flag indicators and other causes of symptoms, such as coeliac disease, have been ruled out, a positive diagnosis of irritable bowel syndrome can be made. Giving a positive diagnosis will help to reduce unnecessary anxiety in people with symptoms of irritable bowel syndrome.

Quality measures

Structure

Evidence of local arrangements to ensure that adults with symptoms of irritable bowel syndrome are given a positive diagnosis if no red flag indicators are present and investigations identify no other cause of symptoms.

Data source: Local data collection.

Process

Proportion of adults with symptoms of irritable bowel syndrome who receive a positive diagnosis if no red flag indicators are present and investigations identify no other cause of symptoms.

Numerator – the number in the denominator who receive a positive diagnosis of irritable bowel syndrome.

Denominator – the number of adults with symptoms of irritable bowel syndrome who have no red flag indicators and investigations identify no other cause of symptoms.

Data source: Local data collection.

Outcomes

a) Incidence of irritable bowel syndrome.

Data source: Local data collection, for example, from Read‑coded patient records on GP clinical information systems.

b) Satisfaction with the irritable bowel syndrome diagnostic process.

Data source: Local data collection.

What the quality statement means for service providers, healthcare professionals and commissioners

Service providers (GP practices) ensure that adults with symptoms of irritable bowel syndrome are given a positive diagnosis if no red flag indicators are present and investigations identify no other cause of symptoms.

Healthcare professionals in primary care (GPs) give adults with symptoms of irritable bowel syndrome a positive diagnosis if no red flag indicators are present and investigations identify no other cause of their symptoms.

Commissioners (clinical commissioning groups and NHS England) commission services that give adults with symptoms of irritable bowel syndrome a positive diagnosis if no red flag indicators are present and investigations identify no other cause of their symptoms.

What the quality statement means for patients, service users and carers

Adults with symptoms of irritable bowel syndrome (such as constipation, diarrhoea and bloating) are given a diagnosis of irritable bowel syndrome if they have no symptoms that need referral to a hospital consultant (these symptoms are known as red flag indicators) and tests show no other cause of their symptoms.

Source guidance

Definitions of terms used in this quality statement

Positive diagnosis

Positive diagnosis means the diagnosis is not merely one of exclusion. It is based on the person's symptoms meeting the diagnostic criteria for irritable bowel syndrome (symptoms of irritable bowel syndrome) and the findings of investigations ruling out realistic alternatives. A positive diagnosis allows the person with symptoms of irritable bowel syndrome and the GP to work towards symptom control.

[Adapted from Irritable bowel syndrome in adults (NICE guideline CG61) full guideline]

Red flag indicators

These are symptoms that need referral to secondary care. They are signs and symptoms of cancer in line with the NICE guideline on recognition and referral for suspected cancer, and inflammatory markers for inflammatory bowel disease.

[Adapted from Irritable bowel syndrome in adults (NICE guideline CG61), recommendation 1.1.1.2 (key priority for implementation), and expert opinion]

Investigations

Investigations for adults presenting with suspected irritable bowel syndrome should include consideration of signs and symptoms of cancer in line with the NICE guidance on recognition and referral for suspected cancer (for example, sections 1.3 on lower gastrointestinal tract cancers and 1.5 on gynaecological cancers), and inflammatory markers for inflammatory bowel disease.

When the above have been excluded, the following tests should be done to exclude other diagnoses:

  • full blood count

  • erythrocyte sedimentation rate (ESR) or plasma viscosity

  • C‑reactive protein (CRP)

  • antibodies for coeliac disease (endomysial antibodies [EMA] or tissue transglutaminase [TTG]).

The following tests are not necessary to confirm diagnosis in people who meet the diagnostic criteria for irritable bowel syndrome:

  • 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).

[Adapted from Irritable bowel syndrome in adults (NICE guideline CG61), recommendations 1.1.1.2, 1.1.2.1 and 1.1.2.2 (key priorities for implementation)]

Symptoms of irritable bowel syndrome

Irritable bowel syndrome should be considered if an adult presents with abdominal pain or discomfort, bloating or a change in bowel habit for at least 6 months. A diagnosis of irritable bowel syndrome should be considered only if the person has abdominal pain or discomfort that is either relieved by defaecation or is associated with altered bowel frequency or stool form. This should be accompanied by at least 2 of the following 4 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.

Lethargy, nausea, backache and bladder symptoms are also common in people with irritable bowel syndrome, and may be used to support the diagnosis.

[Adapted from Irritable bowel syndrome in adults (NICE guideline CG61), recommendations 1.1.1.1 and 1.1.1.4 (key priorities for implementation)]