Crohn's Disease

Outline

Background 

• Crohn's is an inflammatory condition of the bowel

Assessment

Presentation

• Abdo pain- cardinal symptom

• Bloody diarrhoea, weight loss, subacute symptoms (weeks- months)

• Usually young (< 50) for first presentation

Examination

• Tender abdomen

• Mouth ulcers

• Erythema nodosum, Pyoderma Gangrenosum

Investigations

• Baseline bloods (FBC, U&Es, LFTs, CRP)- raised inflammatory markers, anaemia 

• Haematinics: Fe studies, B12, folate- micro-cytic: IDA, normocytic: ACD, macrocytic B12/folate

• Faecal calprotectin- screening & disease activity; if negative reassuring

• Colonoscopy +- endoscopy: tissue biopsy- often shows non specific inflammation but deeper than would expect with UC

Diagnosis

Diagnostic criteria: 

• Consultant Gastroenterologist: symptoms, signs, investigations

Severity markers:

• > 6 bloody stools pr day with (1/3)

  • Temp> 37.8

  • HR > 90

  • Hb < 105

  • CRP > 30

Differentials: Ulcerative Colitis (UC), Coeliac Disease, Irritable Bowel Syndrome (IBS) 

Management

Acute 

Goals of care: stabilise patient & achieve remission

1. Prednisolone 50mg PO or methylpred 30mg BD 

2. Ciclosporin IV

3. Colectomy

Long term

Goals of care: prevent relapse with minimal side effects

• Mesalazine

• Azathioprine or mercaptopurine if > 2 exacerbations/ year or unable to taper steroids

  • • TPMT levels should be check prior to starting

• Tumour necrosis factor alpha inhibitor, e.g. infliximab 

• Ustekinumab (IL-12 & IL-23 blocker) or Vedolizumab

MDT

• Dietician

• IBD Nurse specialists

• Surveillance colonoscopy (Crohn's colitis increase risk of CRC)

• Imaging +- surgical input for complications

Admission Cycle

Acute Presentation

Admission Bundle

• Management

  • IV Steroids

  • IVF + 'sloppy diet' / PO fluids

  • Vte prophylaxis

  • Consider surgical input

• Investigations: 

  • FBC, U&E, CRP, LFTs

  • Fe studies, B12, folate; TFT

  • Stool culture x3 C.diff & stool chart, blood cultures if pyrexic

  • AXR ? colonic dilatation, CXR

  • Dietician

  • First presentation consider sigmoidoscopy

Daily Review

• Monitor stool frequency, abdo pain

• Monitor weight- response to dieticians; hydration status- ?PO fliuds

• Escalation

  • Gastro- change steroids

  • Consult general surgeons- failure of medical treatment

Discharge

• IBD FU

• Gastro input

• Symptoms stabilising/ acceptable

• Objective marker stabilising/ normalised- Cr, HR, BP, weight

Med Reg Notes

Surgical Referral

• Refractory medical management

• Fistulating, obstruction and perforation

• Colonic dilatation on AXR

Indications for Colectomy

1. Trialed of steroids or ciclosporin for 4 days

2. Failed therapy

   • Bowel movements > 6/d

   • Temp > 38 degrees, BP < 90/60

   • Abdomen tender

   • AXR: caecal/ colonic dilatation

Total vs subtotal colectomy: total colectomy has benefit of being curative but downside of worsening short bowel syndrome. 

Short Bowel Syndrome Complications

• Calcium oxalate urinary stones

Crohns Complications

Crohn's typically affects terminal ileum. Terminal ileum is responsible for B12 and bil acid resorption. Therefore, terminal ileum resection produces: 

1. B12 Deficiency

2. Bile acid induced diarrhoea 

References and Resources

1. https://www.crohnsandcolitis.org.uk/info-support/information-about-crohns-and-colitis/all-information-about-crohns-and-colitis/understanding-crohns-and-colitis/how-to-get-a-diagnosis?utm_term=crohns%20diagnosis&utm_source=google&utm_medium=cpc&gad_source=1&gad_campaignid=882649866&gbraid=0AAAAADL5tijunCO3MaWtr-4kF0nMtRymE&gclid=CjwKCAjwtvvPBhBuEiwAPMijr7luHVYfkNeS8pGsokR3NQpgbe1dV8b0_KRMdnOoYSOvqsdsR-2URBoCSuAQAvD_BwE

Written in 2025