Inflammatory Bowel Disease

Inflammatory bowel disease is the umbrella term for two main diseases causing inflammation of the GI tract: Ulcerative Colitis and Crohn’s disease. They both involve inflammation of the walls of the GI tract and are associated with periods of remission and exacerbation. 


Crohn’s versus Ulcerative Colitis

Crohn’s and ulcerative colitis have features that are distinct from each other that are commonly tested in exams and dictate different management, so it is worth learning these.


Crohn’s (crows NESTS)

N – No blood or mucus (less common)

E – Entire GI tract

S – Skip lesions” on endoscopy

T – Terminal ileum most affected and Transmural (full thickness) inflammation

S – Smoking is a risk factor (don’t set the nest on fire)

Crohn’s is also associated with weight loss, strictures and fistulas.

Ulcerative Colitis (remember U – C – CLOSEUP)

CContinuous inflammation

LLimited to colon and rectum

OOnly superficial mucosa affected

SSmoking is protective

EExcrete blood and mucus

UUse aminosalicylates

PPrimary Sclerosing Cholangitis


  • Diarrhoea
  • Abdominal pain
  • Passing blood
  • Weight loss



  • Routine bloods for anaemia, infection, thyroid, kidney and liver function
  • CRP indicates inflammation and active disease
  • Faecal calprotectin (released by the intestines when inflamed) is a useful screening test (> 90% sensitive and specific to IBD in adults)
  • Endoscopy (OGD and colonoscopy) with biopsy is diagnostic
  • Imaging with ultrasound, CT and MRI can be used to look for complications such as fistulas, abscesses and strictures.


Management of Crohn’s

This section is based on NICE guidelines last updated May 2016. Please see the full guidelines and talk to seniors before treating patients.


Inducing Remission

  • First line: Steroids (e.g. oral prednisolone or IV hydrocortisone)


If steroids alone don’t work, consider adding immunosuppressant medication under specialist guidance:

  • Azathioprine
  • Mercaptopurine
  • Methotrexate
  • Infliximab
  • Adalimumab


Maintaining Remission

Tailored to individual patients based on risks, side effects, nature of the disease and patient’s wishes. It is reasonable not to take any medications whilst well.

First line:

  • Azathioprine
  • Mercaptopurine



  • Methotrexate
  • Infliximab
  • Adalimumab



When the disease only affects the distal ileum it is possible to surgically resect this area and prevent further flares of the disease. Crohns typically involves the entire GI tract

Surgery can also be used to treat strictures and fistulas secondary to Crohns disease.


Management of Ulcerative Colitis

This section is based on NICE guidelines last updated June 2013. Please see the full guidelines and talk to seniors before treating patients.


Inducing Remission

Mild to moderate disease

  • First line: aminosalicylate (e.g. mesalazine oral or rectal)
  • Second line: corticosteroids (e.g. prednisolone)


Severe disease

  • First line: IV corticosteroids (e.g. hydrocortisone)
  • Second line: IV ciclosporin


Maintaining Remission

  • Aminosalicylate (e.g. mesalazine oral or rectal)
  • Azathioprine
  • Mercaptopurine



Ulcerative colitis typically only affects the colon and rectum. Therefore, removing the colon and rectum (panproctocolectomy) will remove the disease. The patient is then left with either a permanent ileostomy or something called an ileo-anal anastomosis (J-pouch). This is where the ileum is folded back in itself and fashioned into a larger pouch that functions a bit like a rectum. This “J-pouch” which is then attached to the anus and collects stools prior to the person passing the motion.


Last updated February 2019