Rational referrals: Gastroenterology

In the first of a new series on navigating referral pathways, specialists Dr Michael Colwill and Dr Andrew Poullis advise on how to stratify gastroenterology cases

With NHS waiting lists increasing,¹ there is pressure on GPs to select appropriate patients to refer to secondary care more efficiently, while not missing serious pathology. Knowing when and how to refer is particularly challenging for gastroenterological complaints given the high level of symptom crossover between different pathologies. This article aims to offer pragmatic guidance to GPs about referral and where maximising primary care investigations can be of benefit. 

Advice and guidance
Advice and guidance (A&G) is integral to the NHS Long Term Plan to reduce secondary care outpatient consultations. However, A&G services vary and while the approach can be effective, response times are variable and it might be difficult to have a fluent dialogue with a specialist. 

We feel the most effective use is to answer specific questions. These can include:

• Management plans for patients with known gastroenterological diagnoses who are experiencing a deterioration in symptoms.
• Clarification of a patient’s test results.
• Advice on whether a referral to secondary care is appropriate.
• Follow-up of incidental findings, such as gallbladder polyps seen on ultrasound.

Same-day referrals
Inflammatory bowel disease
Most urgent referrals are easily identified, but in our experience inflammatory bowel disease (IBD) is an area that causes difficulties. Clinical suspicion of IBD, or a flare of a patient with known IBD, should prompt assessment using the Truelove and Witts criteria. If they are classed as severe – for instance if there are six or more bloody stools per day plus systemic symptoms (pyrexia, tachycardia, anaemia, elevated inflammatory markers) – referral to a same-day acute medicine clinic or A&E is indicated. If the patient’s condition is not classed as severe, stool cultures, faecal calprotectin, routine blood tests and an urgent referral to gastroenterology are advised. Known IBD patients should be encouraged to contact their IBD advice line if their secondary care provider has one.

Suspected surgical cases
Suspected acute surgical pathology, such as possible bowel obstruction, abdominal pain with new jaundice, suspected appendicitis and upper gastrointestinal (GI) bleeding should all be referred for same-day assessment.

Liver cirrhosis
Patients presenting with decompensated liver cirrhosis, characterised by new-onset jaundice, ascites, hepatic encephalopathy, coagulopathy or variceal haemorrhage in a known cirrhotic patient require same-day assessment. In a non-cirrhotic patient presenting acutely with jaundice (bilirubin over 40), significantly abnormal LFTs (ALT over 300 IU/l), low albumin or prolonged INR then same-day gastroenterology advice should be sought and either admission or urgent referral to secondary care should be considered. Close community monitoring, such as twice-weekly consultation and bloods, is advised until they have been reviewed in secondary care. 

Acute diarrhoea
Defined as three or more loose or watery stools per day and lasting less than 14 days, acute diarrhoea can cause concern for possible underlying pathology such as IBD. In an otherwise well patient, the vast majority of cases will be due to infection and will resolve within 10 days. We therefore advise stool cultures and good hydration in the first instance without referral to secondary care.² Antimicrobial therapy is controversial but microbiology advice can be sought if it is felt to be indicated. 

Two-week-wait referrals
NICE guidelines set out specific symptoms that should prompt either an urgent suspected cancer (USC) referral or direct access investigation (endoscopic or imaging).³ 

This guidance is under constant review and the British Society of Gastroenterology and Association of Coloproctology of Great Britain and Ireland have recently published updated guidance on the use of the faecal immunochemical test (FIT).⁴ This outlines that patients with a negative FIT (less than 10µgHb/g), normal full blood count and no ongoing concerns of possible colorectal cancer should not be referred under the USC pathway. Instead, safety netting should be implemented by:

• Providing clear information to the patient about new symptoms to be aware of.
• Offering a second FIT test if ongoing clinical concerns remain.
• Referral to a non-specific-symptoms USC pathway.

Although USC pathways focus on a possible cancer diagnosis, there is no doubt that using them can lead to a quicker diagnosis of important benign conditions. In the upper GI USC pathway, young patients with dysphagia rarely have oesophageal cancer but a significant number will have eosinophilic oesophagitis where prompt diagnosis will reduce the risk of bolus impaction and A&E attendance. Likewise, in the lower GI pathway a young patient with a positive FIT is unlikely to have colorectal cancer but this is now the route by which most new diagnoses of IBD are made.  

Routine referrals
While these pathways offer options for urgent pathology, routine appointments can take months to materialise. Maximising investigation and initial treatments in primary care can help to bridge this delay or upgrade patients to a more urgent pathway.

Suspected irritable bowel syndrome (IBS)
IBS is a functional disease of the GI tract, and while the Rome IV criteria can be a useful guide, they are often too rigid to be applied to the majority of patients presenting in primary care. For most gastroenterologists IBS remains a diagnosis of exclusion. Although national guidelines exist for IBS diagnosis and faecal calprotectin use,⁵ we recommend the following strategy for investigating suspected cases of IBS:

• All: FBC, U&Es, LFTs, Ca, HbA1c, TFTs, CRP, vitamin D, coeliac antibodies.
• Any upper GI symptoms: Helicobacter pylori stool antigen.
• Any lower GI symptoms: faecal calprotectin and FIT.
• Bloating (in females): CA-125.

The blood tests will screen for evidence of malabsorption suggesting significant underlying pathology, which would require referral, and rule out hypercalcaemia or diabetes as the cause of symptoms. Any abnormalities should be referred. If all results are normal this supports an IBS diagnosis. This can then be presented to the patient in a positive manner and initial management started: exercise, probiotics, relaxation techniques and signposting to the NICE IBS dietary sheet.⁶ Dietitian referral can be invaluable and a low FODMAP diet is an effective option if the patient is willing. Persistent symptoms or diagnostic uncertainty should prompt routine referral.

Chronic diarrhoea 
This can be initially investigated in primary care with routine blood tests including FBC, CRP, coeliac serology and TFTs. Stool tests for infection, calprotectin, FIT and elastase are useful. If these investigations do not give a diagnosis and symptoms persist, secondary care assessment is always needed. 

Persistent abdominal pain 
This has a wide differential and can be a challenging symptom to manage. An abdominal ultrasound is a useful first line non-invasive test that is readily available in primary care and can help to rule out several pathologies such as gallstones, renal stones or chronic pancreatitis. 

Reflux symptoms
Reflux that is resistant to proton pump inhibitor (PPI) therapy should be investigated with direct access gastroscopy, to assess for any structural or sinister pathology, and Helicobacter pylori testing. 

If initial PPI therapy does not resolve symptoms, increasing the dose followed by addition of an H2-receptor antagonist (such as famotidine) and then possible addition of a prokinetic is a reasonable treatment algorithm. Persistent symptoms or unclear diagnosis require routine referral. 

Abnormal liver function tests (LFTs)
Deranged LFTs can pose a challenge for GPs who must decide how to act upon findings that are often incidental. The criteria for same-day advice were discussed earlier but for other cases, follow the thorough algorithm published by Camden CCG, available free.^7,8 It incorporates the use of non-invasive fibrosis assessments for non-alcoholic fatty liver disease (NAFLD) such as FIB-4 scoring. A FIB-4 score of less than 1.3 (less than 2.0 in those over 65 years old) identifies patients at low risk of advanced fibrosis who should be managed in primary care, a score of 1.3-3.25 identifies those who should undergo ELF testing and an ELF score of more than 9.5 or a FIB-4 score of more than 3.25 (2.67 if over 65 years old) should prompt routine referral to hepatology services. Those that are managed in primary care should be screened for the other components of metabolic syndrome and undergo annual assessment of their cardiovascular risk and FIB-4 score. A 10% weight loss has been shown to improve liver fibrosis and is a sensible goal for overweight patients. The British Liver Trust is a good source of information for patients and clinicians on this.⁹

Dr Michael Colwill is a specialist registrar in gastroenterology and Dr Andrew Poullis is a consultant gastroenterologist at St George’s Hospital, London

References

1.  BMA. NHS backlog data analysis. 2022. Link
2. Casburn-Jones A, Farthing M. Management of infectious diarrhoea. Gut 2004;53:296-305. Link
3. NICE. Suspected cancer: recognition and referral. NG12. 2015. Link
4. Monahan K, Davies M, Abulafi M et al. Faecal immunochemical testing (FIT) in patients with signs or symptoms of suspected colorectal cancer (CRC): a joint guideline from the Association of Coloproctology of Great Britain and Ireland (ACPGBI) and the British Society of Gastroenterology (BSG) Gut 2022;71:1939-62. Link
5. Vasant D, Paine P, Black C et al. British Society of Gastroenterology guidelines on the management of irritable bowel syndrome. Gut 2021;70:1214-40. Link
6. British Dietetic Association. Irritable Bowel Syndrome (IBS) and diet: Food Fact Sheet. 2008. Link  
7. Rosenberg W, Camden CCG. Adult abnormal liver function tests guidance. 2019. Link 
8. Newsome P, Cramb R, Davison S et al. Guidelines on management of abnormal liver blood tests. Gut 2018;67:6-19. Link
9. British Liver Trust. NAFLD, NASH and fatty liver disease. Link