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1.5 Chronic bowel disorders

Chronic bowel diseases include ulcerative colitis and Crohn’s disease. Aminosalicylates, corticosteroids and drugs that affect the immune response form the basis of drug treatment.

The following guidelines apply:

  • NICE NG129 covers Crohn’s disease
  • NICE NG130 covers Ulcerative Colitis
  • Refer to CKS and ECCO for further information on the prescribing of aminosalicylates in ulcerative colitis and Crohn’s disease
  • NICaN Referral Guidance for Suspected Cancer (Red Flag Criteria)

Fistulating Crohn’s disease

Managing flare-ups in patients who have been diagnosed by a specialist as part of a care plan:
1st choiceMetronidazole 400mg tablets, 500mg tablets, metronidazole (as benzoate) 200mg/5 ml suspensionDose: 10-20mg/kg daily orally in divided doses (usual dose 400-500mg three times daily); usually for 1 month but no longer than 3 months because of concerns about peripheral neuropathy
Ciprofloxacin 500mg tablets, 250mg/5 ml suspension Dose: 500mg twice daily orally

Prescribing Notes

  • Patients with flare-ups should generally be referred back to secondary care for assessment.
  • Patients who have been diagnosed with fistulating Crohn’s disease by a specialist may sometimes be managed in primary care when they present with flare-ups, provided they have previously responded and this is part of the care plan for the patient.
  • Azathioprine is used as a second-line treatment for fistulating Crohn’s disease and continued for maintenance.


  • Systemic fluoroquinolone antibiotics can cause long-lasting disabling and potentially irreversible side effects; they must now only be prescribed when other commonly recommended antibiotics are inappropriate – see MHRA