Crohn’s Disease


Crohn's disease is a chronic, relapsing-remitting, non-infectious inflammatory disease of the gastrointestinal tract.  Crohn's disease and ulcerative colitis are collectively known as 'inflammatory bowel disease'.  The two conditions can usually be distinguished by the nature of the inflammation they cause.  With Crohn's disease the full thickness of the intestinal wall becomes inflamed, whereas with ulcerative colitis the inflammation is limited to the intestinal mucosa.  Crohn's disease is thought to be an immune-mediated condition caused by environmental triggering events in genetically susceptible people.  The exact incidence and prevalence rates of Crohn's disease are not known, as detection rates and diagnostic criteria differ between studies but it is thought to be around 10.6 per 100,000 people in the UK


When to suspect Crohn's disease

NOTE The diagnosis of Crohn's disease may be difficult as it has unpredictable relapses and remissions, and clinical features vary with age, onset (insidious or acute), the site(s) of disease, and the presence or absence of complications and extra-intestinal manifestations

Suspect Crohn's disease in people who have:

  • Otherwise unexplained persistent diarrhoea (frequent loose stools for more than 4–6 weeks), including nocturnal diarrhoea
  • In Crohn's colitis, there may be faecal urgency, tenesmus (the desire to defecate while passing little or no stool), and blood or mucus in the stool
  • Abdominal pain or discomfort — this may be due to adhesions, fistulas, intestinal obstruction or dilatation, or mucosal inflammation with active Crohn's disease
  • Weight loss, faltering growth or delayed puberty in children
  • Non-specific symptoms such as fatigue, malaise, anorexia, or fever


On examination there may be:

  • Pallor, clubbing, aphthous mouth ulcers
  • Abdominal tenderness or mass, for example in the right lower quadrant
  • Perianal pain or tenderness, anal or perianal skin tag, fissure, fistula, or abscess
  • Signs of malnutrition and malabsorption — serial weight loss or, in children, faltering growth or delayed puberty
  • Eye, skin, or joint signs of extra-intestinal manifestations


Suspect a complication of Crohn's disease if there is:

  • A history of recurrent urinary tract infections and passing gas or faeces in the urine — may suggest a fistula allowing faecal leakage into the bladder
  • A history of passing gas or faeces through the vagina — may suggest a fistula allowing faecal leakage into the vagina
  • Perianal discharge of mucus or pus — may suggest a fistula allowing faecal leakage through the perianal skin
  • Partial bowel obstruction (abdominal colicky pain and distention; diarrhoea due to stasis of bowel contents and bacterial overgrowth) or complete bowel obstruction (severe abdominal pain, vomiting, no flatus and complete constipation) — may suggest intestinal stricture



If a diagnosis of Crohn's disease is suspected, consider arranging the following investigations in primary care, depending on local availability:

  1. FBC — anaemia may be due to blood loss, malabsorption, or malnutrition; an increased platelet count may suggest active inflammation
  2. CRP and ESR — may be raised if there is active inflammation or an infectious complication
  3. U&Es — to assess for electrolyte disturbance and signs of dehydration
  4. LFTs, including albumin — a low serum albumin may indicate protein-losing enteropathy
  5. Ferritin, vitamin B12, folate, and vitamin D levels — may be nutritional deficiencies due to malabsorption or intestinal losses
  6. Coeliac serology — to exclude coeliac disease
  7. Stool microscopy and culture, including Clostridium difficile toxin — to exclude infective gastroenteritis or pseudomembranous colitis
    1. NOTE The diagnosis of a pathogen does not exclude a diagnosis of Crohn's disease, as a first episode may be triggered by enteric infection
  8. Faecal calprotectin (a faecal white cell marker, for adults) — if raised may suggest active inflammation (compared with a normal result which is expected in irritable bowel syndrome)

NOTE:  Be aware that investigation results may be normal in a person with active Crohn's disease


Management of suspected Crohn's disease

  1. Arrange an emergency hospital admission if the person is systemically unwell with symptoms of bloody diarrhoeafevertachycardia, or hypotension
  2. If hospital admission is not needed, arrange an urgent referral to a paediatric gastroenterologist for children or gastroenterologist for adults, for specialist investigations to confirm the diagnosis and to initiate treatment
    1. NOTE:  Do not prescribe anti-diarrhoeal drugs if the clinical diagnosis is uncertain, as they may precipitate toxic megacolon in people with ulcerative colitis
  3. Arrange a referral to an appropriate specialist (such as rheumatology, dermatology, or ophthalmology) if appropriate, if there are suspected extra-intestinal manifestations


Management of confirmed Crohn's disease

Arrange to review the person regularly in primary care, depending on clinical judgement and the frequency of specialist gastroenterology follow-up

  1. Assess the impact of symptoms on daily functioning such as home, work, school, and leisure activities, and assess for associated anxietyand/or depression
  2. Provide advice on Crohn's disease and offer sources of information and support such as Crohn's and Colitis UK and CICRA (Crohn's in Childhood Research Association).  Booklets and guides for how to manage symptoms can be found here and key booklets can also be found individually under the 'Supporting Information' tab
  3. Encourage the person to stop smoking, if needed and appropriate, as this may reduce the risk of relapse.  See information on the Kent Stop Smoking Service and an information sheet on 'Smoking and IBD' booklet (Crohn's and Colitis UK)
  4. Assess the person's risk of osteoporosis, including dietary calcium intake, and extent of Crohn's disease and history of small bowel resection, and manage appropriately.  See information on Osteoporosis and an information sheet on 'Bones and IBD' booklet (Crohn's and Colitis UK)
  5. Ensure that the person has follow-up arranged with a gastroenterology specialist, if needed, and encourage the person to attend appointments regularly
  6. Prescribe and monitor specialist drug treatments if a shared-care agreement is in place, if appropriate, and encourage the person to take medication regularly as prescribed
  7. Assess for clinical features suggesting a Crohn's disease flare-up or other troublesome symptoms (see sections below), and manage appropriately
  8. Arrange a referral to an appropriate specialist (such as rheumatology, dermatology, or ophthalmology) if appropriate, if there are suspected extra-intestinal manifestations
  9. If the person is taking immunosuppressive or biologic therapyensure they are aware that live vaccines are contraindicated and these vaccines should only be given before the start of specialist treatment, and they are at increased risk of influenza and pneumococcal infection and should receive appropriate vaccinations regularly


Management of a Crohn's flare up

Arrange an emergency hospital admission if the person has a suspected flare-up of Crohn's disease and is systemically unwell with severe symptoms, such as:

  1. Severe diarrhoea (more than 6–8 stools a day)
  2. Feverdehydrationtachycardia, or hypotension
  3. Suspected intestinal obstruction or intra-abdominal or perianal abscess
  4. Cachexia with a BMI less than 18.5 kg/m2, or unintended sudden weight loss
  5. Persistent symptoms despite optimal management in primary care

NOTE:  A raised serum CRP level may be suggestive of a severe disease flare-up


If admission to hospital is not needed:

  1. Consider whether symptoms may be due to an alternative diagnosis, and manage appropriately
  2. Check the person's adherence to their current drug treatment regimen, and encourage them to take medication regularly and appropriately
  3. Consider arranging an urgent specialist gastroenterology review appointment or seeking specialist advice
  4. Consider prescribing drug treatment for disease flare-ups according to the person's shared-care agreement, such as starting a tapered course of oral corticosteroids, if appropriate, whilst awaiting specialist review
  5. Consider arranging a referral to a dietitian if there are signs of unintended weight loss or malnutrition


If there are recurrent flares of disease activity, seek specialist advice regarding whether the person's maintenance treatment regimen needs to be changed, or whether surgery may be needed


Management of associated symptoms

NOTE If there are troublesome symptoms associated with Crohn's disease, ensure that the person's maintenance treatment is optimal and seek specialist advice if necessary

The following management strategies may be appropriate in primary care:

  1. Diarrhoea
    1. Exclude any alternative cause for diarrhoea symptoms, such as infection, abscess formation, dysmotility, bacterial overgrowth, bile salt malabsorption, or drugs, and manage appropriately
    2. If diarrhoea symptoms persist, consider whether symptomatic treatment is appropriate, following specialist advice if necessary
  2. Fistulas and strictures
    1. If a fistula or intestinal stricture is suspected, arrange hospital admission, arrange a referral to colorectal surgery, or seek specialist advice, depending on clinical judgement
  3. Upper gastrointestinal symptoms
    1. If the person has previously been investigated for upper gastrointestinal symptoms, manage the underlying cause appropriately.  See Dyspepsia and GORD and Dyspepsia in Pregnancy for more information
  4. Abdominal or perianal pain
    1. Identify the underlying cause for abdominal or perianal pain, wherever possible, to allow appropriate management, including offering analgesia to relieve symptoms
  5. Fatigue
    1. Exclude any alternative or contributing cause for persistent fatigue (such as pain, anaemia, reduced nutritional intake and activity levels, sleep disturbance, stress, anxiety, or depression), and manage appropriately
  6. Oral problems
    1. If the person develops suspected oral lesions secondary to Crohn's disease (such as mucosal tags, 'cobblestoning' [close-packed mucosal nodules], aphthous ulcers, or angular cheilitis), arrange a gastroenterology clinic review appointment and/or referral to a specialist in oral medicine, depending on clinical judgement


Fertility, pregnancy and breastfeeding with Crohn's disease

Contraception advice

  • For women with Crohn's disease, the choice of contraceptive method may be influenced by factors such as malabsorption, surgical history, prolonged immobility, extra-intestinal manifestations such as primary sclerosing cholangitis, and associated conditions such as osteoporosis and venous thromboembolism
  • See the guidance document FSRH UKMEC 2016 - Eligibility Criteria on Contraception Use for detailed information on prescribing contraception for women with inflammatory bowel disease


Fertility advice

  1. Advise women with Crohn's disease that:
    1. Active disease may reduce fertility rates, and inactive disease should not affect fertility
    2. Women who have abdominal or pelvic sepsis, surgery or adhesions may be at increased risk of impaired tubal function
    3. Drug treatment with methotrexate may affect oogenesis and fertility
  2. Advise men with Crohn's disease that:
    1. Fertility is unlikely to be affected for most men with Crohn's disease, but pelvic surgery may lead to erectile dysfunction or ejaculatory problems
    2. Drug treatment with sulfasalazine or methotrexate may affect spermatogenesis, however, the effect should be reversible on stopping treatment. Infliximab may affect semen quality by reducing motility in some men
  3. Offer sources of support and information, such as the information sheet 'Fertility and IBD' booklet (Crohn's and Colitis UK)


Pregnancy advice

  1. Advise women and men they need to be referred to a gastroenterologist before trying to conceive if they are planning a pregnancy
  2. If a woman has a planned pregnancy, ensure she is managed jointly by a gastroenterologist and obstetrician with appropriate expertise
  3. If a woman has an unplanned pregnancy and is prescribed:
    1. Methotrexate, infliximab, or adalimumab, seek immediate specialist advice from a gastroenterologist and/or a specialist in fetal medicine about stopping and changing treatment and starting folic acid supplementation
    2. Other medication, advise the woman to continue maintenance drug treatment, start folic acid supplementation, and arrange an urgent specialist gastroenterology review appointment to ensure that management of Crohn's disease is optimized
  4. If a woman has had significant pelvic surgery, extensive perianal disease, or active rectal involvement, she may be offered elective Caesarean section to reduce the risk of potential anal sphincter damage
  5. Offer sources of support and information, such as the information sheet 'Pregnancy and IBD' booklet (Crohn's and Colitis UK)


Breastfeeding advice

  1. If a woman with Crohn's disease wishes to breastfeed, seek specialist gastroenterology advice if there is any uncertainty about the safety of breastfeeding while prescribed specialist medication
    1. NOTE:  Some drug treatments such as methotrexate, adalimumab, loperamide, ciprofloxacin, and high-dose metronidazole may need to be stopped while breastfeeding, and alternative medication started by a specialist if needed


Abdominal Pain Poster


Blood tests / Phlebotomy

If your practice does not have a practice nurse who is trained to take bloods, you can refer a patient to the Pathology Department at East Kent Hospitals for a blood test (find details here)

Alternatively, Buckland Hospital (Dover) and the Royal Victoria Hospital (Folkestone) both operate a walk-in service where no appointment is necessary, except for if the patient requires a Glucose Tolerance Test (GTT).  In the event that a GTT is required, please call 01304 222552 (for Buckland) and 01303 854484 (for Royal Victoria) to arrange a suitable appointment

Please ensure that the patient remembers to take with them their blood test form to the walk-in centres

Advice and Guidance is being made available for all specialties, and is being provided by consultant specialists at East Kent Hospitals.  To make a request or to check to if a query has been answered, you will need to log in via the electronic Referral System (eRS)

Click here for the "how to access" e-Referral Advice and Guidance Manual for instructions on how to make a request and check responses

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