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

• Unintentional weight loss
• Unexplained rectal bleeding
• Family history of bowel or ovarian cancer
• Abdominal mass
• Rectal mass
• Iron Deficiency Anaemia
• Nocturnal diarrhoea

Refer on the suspected colorectal cancer pathway:

• aged 40 and over with unexplained weight loss and abdominal pain

Consider referral on the suspected colorectal cancer pathway:

• aged under 50 with rectal bleeding and any of the following unexplained symptoms or findings :

a. abdominal pain;

b. change in bowel habit;

c. weight loss;

d. iron-deficiency anaemia

Please see the suspected cancer NICE guidelines NG12 .

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 over 37.8°C; CRP greater than 30 mg/L; Hb less than 108 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.

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.
• 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)
• Consider Ca-125 for ovarian cancer in women
• 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

CAUTION: 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 Ψ

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.

Calprotectin pathway 

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 symptoms remain troublesome, 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 100-250 µg/g

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

If repeat faecal calprotectin lower than 100 µg/g

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

If repeat faecal calprotectin 100-250 µg/g

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

c) 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

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 over 37.8°C; CRP greater than 30 mg/L; Hb less than 108 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.

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 psychology support. GP referral or patient self-referral to:

Improving Lives Plymouth – West Devon

Talkworks – South, North, East Devon

Lifestyle

• Lifestyle
  
  • Create and use relaxation time and increase physical activity where appropriate
• Dietary advice
  
  • If diet thought to play a role in an individuals’ symptomatology

a) Give advice on general dietary measures:

• Eat regular meals
• Reduce alcohol, fizzy drinks and caffeine
• Maintain adequate hydration - drink at least 8 cups water per day
• 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.
• 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
• 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

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 Specialist Dietetic Services.

A faecal calprotectin is not necessary for GPs to make a diagnosis of IBS but it is necessary for onward referral to gastroenterology and specialist dieticians.

Referrals should only go on to secondary care gastroenterology with a negative faecal calprotectin (lower than 50 µg/g) 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.
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)
• Faecal calprotectin numerical value
• Strategies tried and failed so far in primary care and if specialist dietitian input received

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

1. If faecal calprotectin 50-100 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.

2. If faecal calprotectin 100-250 µg/g: repeat the calprotectin test within 2 weeks (and ensure that stool culture sent already)

• 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 urgently to gastroenterology and highlight that suspected IBD

3. If 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:
4. Full Blood Count (FBC)
5. Coeliac serology with IgA levels
6. C-reactive Protein (CRP)
7. If diarrhoea: stool for MCS (OCP - if travel or at risk)
8. Faecal calprotectin numerical value

Referral Instructions

Pathway 1: Specialist Dietician pathway

e-Referrals Service Selection

Specialty: Dietetics

Clinic Type: Gastroenterology

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

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

Referral Form

DRSS Referral Form

Patient Information

My Health Devon

The IBS Network

Improving Lives Plymouth

Talkworks

NHS IBS patient webinars

Guts Charity

Evidence

1. NICE guideline CG61 last updated April 2017
2. NICE DG11 2013
3. BSG IBS 2021 guidance: Vasant DH, Paine PA, Black CJ, Houghton LA, Everitt HA, Corsetti M, Agrawal A, Aziz I, Farmer AD, Eugenicos MP, Moss-Morris R, Yiannakou Y, Ford AC. British Society of Gastroenterology guidelines on the management of irritable bowel syndrome. Gut. 2021 Apr 26:gutjnl-2021-324598. doi: 10.1136/gutjnl-2021-324598. Epub ahead of print. PMID: 33903147.
4. Walker, GJ, Moore, L, Heerasing, N, et al. Faecal calprotectin effectively excludes inflammatory bowel disease in 789 symptomatic young adults with/without alarm symptoms: a prospective UK primary care cohort study. Aliment Pharmacol Ther. 2018; 47: 1103– 1116. https://doi.org/10.1111/apt.14563
5. Menees SB, Powell C, Kurlander J, Goel A, Chey WD. 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. Am J Gastroenterol. 2015 Mar;110(3):444-54. doi: 10.1038/ajg.2015.6. Epub 2015 Mar 3. PMID: 25732419.
6. Turvill J, Turnock D. Audit of the impact of the York faecal calprotectin care pathway on colonoscopy activity. Frontline Gastroenterol. 2019 Oct 24;11(4):285-289. doi: 10.1136/flgastro-2019-101315. PMID: 32587672; PMCID: PMC7307046.
7. Turvill J, Turnock D, Holmes H, Jones A, Mclaughlan E, Hilton V, Marriott S. Evaluation of the clinical and cost-effectiveness of the York Faecal Calprotectin Care Pathway. Frontline Gastroenterol. 2018 Oct;9(4):285-294. doi: 10.1136/flgastro-2018-100962. Epub 2018 Jun 7. PMID: 30245791; PMCID: PMC6145433.
8. Holmes H, McMaster J, Davies H, Vaines V, Turvill J. Evaluation of the Cost-Utility of the York Faecal Calprotectin Care Pathway. Expert Rev Pharmacoecon Outcomes Res. 2020 Apr 19:1-8. doi: 10.1080/14737167.2020.1751613. Epub ahead of print. PMID: 32249622.
9. Turvill J, Aghahoseini A, Sivarajasingham N, Abbas K, Choudhry M, Polyzois K, Lasithiotakis K, Volanaki D, Kim B, Langlands F, Andrew H, Roos J, Mellen S, Turnock D, Jones A. Faecal calprotectin in patients with suspected colorectal cancer: a diagnostic accuracy study. Br J Gen Pract. 2016 Jul;66(648):e499-506. doi: 10.3399/bjgp16X685645. Epub 2016 Jun 6. PMID: 27266863; PMCID: PMC4917053.
10. Turvill J, O'Connell S, Brooks A, Bradley-Wood K, Laing J, Thiagarajan S, Hammond D, Turnock D, Jones A, Sood R, Ford A. Evaluation of a faecal calprotectin care pathway for use in primary care. Prim Health Care Res Dev. 2016 Sep;17(5):428-36. doi: 10.1017/S1463423616000049. Epub 2016 Feb 22. PMID: 26899214.
11. Turvill J, O'Connell S, Brooks A, Bradley-Wood K, Laing J, Thiagarajan S, Hammond D, Turnock D, Jones A, Sood R, Ford A. Evaluation of a faecal calprotectin care pathway for use in primary care. Prim Health Care Res Dev. 2016 Sep;17(5):428-36. doi: 10.1017/S1463423616000049. Epub 2016 Feb 22. PMID: 26899214.

Pathway Group

This pathway was signed off by NHS Devon

Publication date: May 2021

Updated: February 2024