Pathway for Diagnosis and Management of Irritable Bowel Syndrome in Adults Aged 18-50 years old

Signs and Symptoms

NICE guideline definition of IBS = abdominal pain or discomfort, in association with altered bowel habit, for at least 6 months, in the absence of alarm symptoms or signs

Consider IBS when the patient presents with:

• Abdominal pain
• Bloating
• Change of bowel habit
• This is usually accompanied by at least two of the following:
  • Related to defecation
  • Associated with a change in bowel habit
  • Associated with a change in stool form (appearance)
  • Passage of mucous
  • Other features such as lethargy, nausea, depression/anxiety, fibromyalgia, backache & bladder symptoms are common in people with IBS and may be used to support the diagnosis.

Consider common drug causes of GI upset including:

• NSAIDs, PPIs, SSRIs, Metformin, Statins, Laxatives

History and Examination

The classification of IBS patients into sub-groups is useful for clinical practice, but it is common for IBS patients to switch from one subtype to another over time. More than 75% of IBS patients change to either of the other 2 subtypes at least once over a 1-year period.

Based on the history, IBS can be divided into:

IBS-D = diarrhoea predominant

IBS-C = constipation predominant

IBS-mixed = alternating

Differential Diagnoses

Differential diagnoses may include:

• Inflammatory Bowel Disease (IBD)
• Coeliac disease
• Chronic pancreatitis or pancreatic insufficiency (perform faecal elastase)
• Bile acid malabsorption (common following cholecystectomy)
• Malignancy
• Infection

Diagnostic uncertainty between IBS and IBD

Please see the suspected cancer NICE guidelines NG12 and the latest local DG30 guidelines for faecal immunochemical testing (FIT) in patients 50 years and over.

• Unexplained weight loss
• Rectal bleeding
• Family history of bowel or ovarian cancer
• Age over 60 and change of bowel habit lasting over 6 weeks
• Iron Deficiency Anaemia
• Rectal or abdominal mass

Patients presenting with these symptoms need to be investigated/ referred to secondary care through the 2 week wait pathway

In adults aged 18-50 years old, with symptoms suggestive of IBS please organise routine blood tests:

• Full Blood Count (FBC)
• Coeliac serology and IgA
  • Please do not repeat if previously performed in last 3 years and send irrespective of predominant stool pattern
  • Consume gluten in more than 1 meal per day for longer than 6 weeks before testing (NICE)
  • Use total IgA and IgA tTG as 1st choice test
  • Use IgA endomysial antibodies (EMA) if IgA tTG is weakly positive
  • Consider using IgG EMA, IgG deamidated gliadin peptide (DGP) or IgG tTG if IgA deficient when IgA tTG is unreliable and may result in false negative test
  • Discuss with duty biochemist or gastroenterologist if uncertain on diagnosis of coeliac disease. The BSG has issued interim guidance using a new non-biopsy-based protocol for coeliac disease during COVID-19 pandemic to help ease demands on diagnostic services.
• C-reactive Protein (CRP)
  • Meta-analysis has shown that patients with typical IBS symptoms and CRP lower than 5mg/L had a lower than 1% likelihood of IBD
• Consider checking thyroid function tests (TFTs), renal function and corrected calcium
• If diarrhoea, send stool for microscopy, culture and sensitivity (MCS) (add OCP only if travel or at risk)
• Do not do USS / bowel imaging or H. Pylori testing unless appropriate to rule out another condition – no test will 'rule-in' IBS.

If the above bloods tests are normal, but you still suspect IBD, please organise a faecal calprotectin test

Ψ Acute Severe Ulcerative Colitis

Definition: ≥ 6 bloody stools per day AND one or more of following: temp greater than 37.8°C; CRP greater than 30 mg/L; Hb lower than 108 g/L; pulse greater than 90 bpm. If the patient meets these criteria, contact the on-call Consultant Gastroenterologist and/or admit through medical take out of hours. A faecal calprotectin is not needed in this situation and will delay urgent hospital care.

• Ask patients to sample first bowel movement of the day and try to return faecal sample to the GP practice on the same day.
• Don’t delay sending faecal calprotectin sample to stop PPI or NSAIDs for 2 weeks – these medications can be stopped at time of sending so that improvement in symptoms can be ascertained and repeat calprotectin sent if necessary.

About the faecal calprotectin stool test

• Calprotectin is a protein released into the gastrointestinal tract when it is inflamed, such as in IBD (Crohn's disease, ulcerative colitis an IBD-unclassified) - it is a stable protein, so can be detected in the stool by laboratory assay.
• Elevated levels of faecal calprotectin are found in IBD. Whilst calprotectin is sensitive it is not specific and raised calprotectin levels are found in other treatable organic diseases including diverticulitis, colorectal cancer and polyps; a raised calprotectin therefore warrants onward referral.
• By contrast, in functional disorders of the gastrointestinal tract, such as the irritable bowel syndrome (IBS) faecal calprotectin levels are normal.
• Clinically, it can be difficult to be able to distinguish IBS from IBD based on symptoms, signs and blood tests. Here, faecal calprotectin can be used as a biomarker to support your assessment.
• No biomarker test is 100% accurate, but this IBS care pathway has been shown to be effective and safe in supporting your clinical decision making.

Calprotectin pathway (see flow chart)

a) Faecal calprotectin lower than 100 µg/g:

• IBS is 98% likely
• Recommend lifestyle, dietary and/or pharmacotherapy treatment
• GP to review symptoms have improved in 6 weeks’ time
  • If still symptomatic at review, consider urological and gynaecological diagnoses (consider Ca-125 +/- ovarian USS in women presenting with new IBS aged over 50 yrs)

At 6 weeks: If symptoms remain troublesome AND still no red flags AND faecal calprotectin is lower than 50 µg/g:

• IBS is 99% likely
• Treat with second line IBS therapies and consider referral to specialist dieticians before routine gastroenterology referral or advice & guidance

At 6 weeks: If symptoms remain troublesome AND still no red flags AND faecal calprotectin is 50-99 µg/g:

• IBS is 81% likely, therefore GP to consider routine gastroenterology referral or advice & guidance

b) Faecal calprotectin ≥ 100 µg/g

• Repeat the calprotectin test within 2 weeks (and ensure that stool culture sent already)

In an unwell patient with acute abdominal pain or significant bloody diarrhoea and possible IBD, do not let primary care investigations delay appropriate urgent assessment. Look for signs of toxicity: ≥ 6 bloody stools per day and one or more of following: temp greater than 37.8°C; CRP greater than 30 mg/L; Hb lower than108 g/L; pulse greater than 90 bpm. If toxicity present or clinical concern contact the on-call Consultant Gastroenterologist and/or admit through medical take.

If repeat faecal calprotectin lower than 100 µg/g

• IBS is 98% likely, see above for management of IBS

If repeat faecal calprotectin 100 - 250 µg/g

• Inflammatory Bowel Disease is 12% likely, refer routinely to gastroenterology and highlight that suspected IBD

If repeat faecal calprotectin greater than 250 µg/g

• Inflammatory Bowel Disease is 46% likely, refer urgently to gastroenterology and highlight that suspected IBD for consideration of straight-to-test investigation

Primary care management

A positive diagnosis of IBS always helps management: patients without 'red flags' and with normal tests should be managed in primary care.

Please see MyHealth Devon website and BSG guidance for strategies to manage IBS symptoms

In general, treatment is targeted at addressing a patient’s most troublesome symptoms, be that abdominal pain, diarrhoea, constipation or bloating.

• Reassurance and explanation about the condition

Explain how gut and mind interact.

Exacerbating factors include post infective, e.g. after gastroenteritis (over half generally settle over time although this may take a few years and is more typically causes IBS-D than IBS-C) and 'Stress', e.g. bereavement, interpersonal relationships.

Common misconceptions and concerns in IBS patients include:

• lower than 1/3 know abdominal pain is a key symptom of IBS
• 40% think colonoscopy can diagnose IBS
• 30% believed IBS increases the risk of developing IBD
• 1 in 7 believe IBS can lead to cancer

Adjust expectations: 2 in 3 patients experience chronic symptoms with treatment targeted at improving symptoms, rather than complete symptom relief

• Signpost to appropriate online resources:
  • My Health Devon
  • NHS IBS patient webinars
  • IBS Network self-help support
  • Guts Charity
• Actively look for and manage co-existing anxiety and depression:
  • For patients with mild/moderate depression and anxiety consider referral to talking therapies support. GP referral or patient self-referral to:
    • Improving Lives Plymouth – West Devon
    • Talkworks – South, North, East Devon

• Lifestyle
  • Explore the impact of symptoms on lifestyle and, if applicable, encourage the person to re-engage in activities and social connections which are meaningful to them. Recommend an increase in physical, and other, activity where appropriate. Pacing may be appropriate when people appear to be doing too much or engaging in activity cycling. Encourage a ‘fixed but flexible’ routine for activities, meals and sleep. Explain links between mood and activity and how these may interact with symptoms. Stress the importance of getting an even balance of time spent doing things which are relaxing, enjoyable and other aspects of life.
• Dietary advice
  • If diet thought to play a role in an individuals’ symptomatology

1. 1. Give advice on general dietary measures:
      1. Eat regular meals
      2. Reduce alcohol, fizzy drinks and caffeine
      3. Maintain adequate hydration - drink at least 8 cups water per day
      4. Reduce processed food consumption, try to eat whole foods and cook food at home from scratch. Processed foods contain 'resistant starch' (starch that resists digestion in the small intestine and reaches the colon intact) which exacerbate symptoms.
      5. Limit fresh fruit to 3 portions per day

b. Signpost patients to BDA food fact sheet on IBS and NHS IBS patient webinars

c. Second line dietary interventions

• If first-line dietary advice is ineffective, patients could be considered for assessment and management by a specialist dietitian (including food avoidance and exclusion diets such as low FODMAP)
• Check a faecal calprotectin before referral if not done previously.

For more information on Diet and Lifestyle: see NICE CG61 and BSG

• Pharmacological management
• This should be targeted on the predominant symptoms e.g., pain, diarrhoea or constipation (see Formulary IBS guidance)

Referral Criteria

NOTE: only for patients aged 18-50 years old

IBS is a condition to be primarily managed in the community. In patients with symptoms of IBS and that have not responded to simple lifestyle, dietary and pharmacological therapy as recommended by NICE consider referral to the Specialist IBS Dietetic services.

See:

IBS investigation flow chart

1. Referrals should only go on to secondary care gastroenterology with a negative faecal calprotectin (lower than 50 µg/g) if there remains a significant doubt of the diagnosis of IBS and in refractory cases that have not responded to specialist IBS dietary changes and first- and second-line medical treatment.

If this is the case refer with:

• Full Blood Count (FBC)
• Coeliac serology with IgA levels
• C-reactive Protein (CRP)
• If diarrhoea: stool for MCS (add OCP - if travel or at risk)
• Calprotectin numerical value
• Strategies tried and failed so far in primary care / with dietitians

Note referrals to Gastroenterology with a negative faecal calprotectin ( lower than 50 µg/g) that have not been managed as per this guideline and without the information above will be returned.

2. If faecal calprotectin ≥ 50-99 µg/g:

• Irritable Bowel Syndrome is 81% likely, therefore GP to consider routine gastroenterology referral if either there remains a significant doubt of the diagnosis of IBS and in refractory cases where symptoms remain very troublesome despite IBS dietary changes and first- and second-line medical treatment.

3. If faecal calprotectin ≥ 100 µg/g: repeat the calprotectin test within 2 weeks (and ensure that stool culture sent already)

• If repeat faecal calprotectin 100 - 250 µg/g
  • Inflammatory Bowel Disease is 12% likely, refer routinely to gastroenterology and highlight that suspected IBD
• If repeat faecal calprotectin greater than 250 µg/g
  • Inflammatory Bowel Disease is 46% likely, refer urgently to gastroenterology and highlight that suspected IBD for consideration of being investigated straight-to-test

Please note that referrals to Gastroenterology with a positive faecal calprotectin will be returned without the following information:

• Full Blood Count (FBC)
• Coeliac serology with IgA levels
• C-reactive Protein (CRP)
• If diarrhoea: stool for MCS (OCP - if travel or at risk)
• Faecal calprotectin numerical value
• If repeat faecal calprotectin 100 - 250 µg/g
  • Inflammatory Bowel Disease is 12% likely, refer routinely to gastroenterology and highlight that suspected IBD

• If repeat faecal calprotectin >250µg/g
  • Inflammatory Bowel Disease is 46% likely, refer urgently to gastroenterology and highlight that suspected IBD for consideration of being investigated straight-to-test

Please note that referrals to Gastroenterology with a faecal calprotectin ≥ 100 µg/g will be returned without the following information:

• Full Blood Count (FBC)
• Coeliac serology with IgA levels
• C-reactive Protein (CRP)
• If diarrhoea: stool for MCS (OCP - if travel or at risk)
• Calprotectin numerical value

Referral Instructions

Pathway 1: Specialist Dietician pathway

e-Referrals Service Selection

Specialty: Dietetics

Clinic Type: Gastroenterology

Service: DRSS-Western-Dietetic-Devon CCG -15N

Pathway 2: Suspected IBD for luminal Gastroenterology (to be seen within 2 weeks)

In an unwell patient with acute abdominal pain or significant bloody diarrhoea and possible IBD, do not let primary care investigations delay appropriate urgent assessment, please contact the on-call Consultant Gastroenterologist or use the electronic advice and guidance service.

Pathway 3: Gastroenterology refractory IBS pathway

e-Referral Service Selection

Specialty: GI & Liver

Clinic Type: Lower GI (medical) excl IBD

Service: DRSS-Western-GI & Liver (Medicine & Surgery)-Devon CCG -15N

Please highlight on the referral form that the referral is in relation to refractory IBS

Referral Forms

DRSS referral proforma

Dietician referral template

GP Information

GP Communication - Implementation of the Devon Faecal Calprotectin Care Pathway - Information for GPs

Information on a new workshop for people with a diagnosis of IBS who are living in Devon (not Plymouth)

This is run by Talking Health/Talk Works, and presented by a dietician and psychologist from the gastroenterology team (RDUH/DPT). They envisage these to be ongoing stand-alone workshops.

Please follow the link to more information. The information can be found here under support for managing my IBS TALKWORKS.

Patient Information

Information on a new workshop for people with a diagnosis of IBS who are living in Devon (not Plymouth)

This is run by Talking Health/Talk Works, and presented by a dietician and psychologist from the gastroenterology team (RDUH/DPT). They envisage these to be ongoing stand-alone workshops.

Please follow the link to more information. The information can be found here under support for managing my IBS TALKWORKS.

My Health Devon

The IBS Network

Improving Lives Plymouth

Talkworks

NHS IBS patient webinars

Guts Charity

Evidence

1. NICE guideline CG61 last updated Apr 2017
2. NICE DG11 2013
3. BSG Interim Guidance: Covid-19 specific non-biopsy protocol guidance for those with suspected coeliac disease
4. A meta-analysis of the utility of C-reactive protein, erythrocyte sedimentation rate, fecal calprotectin, and fecal lactoferrin to exclude inflammatory bowel disease in adults with IBS Stacy B Menees ¹, Corey Powell ², Jacob Kurlander ¹, Akash Goel ³, William D Chey ¹
5. J. Turvill et al. Frontline Gastroenterology, 2017.
6. Ford AC, Forman D, Bailey AG, et al. Irritable bowel syndrome: a 10-yr natural history of symptoms and factors that influence consultation behavior. Am J Gastroenterol 2008;103:1229–39.

Pathway Group

This pathway was signed off by NEW Devon CCG Clinical Pathway Group.

Publication date: May 2021