24th July 2023

Management (Crohn’s disease)

There are two focuses of treatment for IBD – inducing remission to control acute flares of symptoms and then maintaining remission by continuing treatment to establish good symptom control.

Assessment of severity

When a patient with Crohn’s disease presents with new or worsening symptoms, it is important to assess the severity, in order to guide management.

One method used to help determine this is the Crohn’s Disease Activity Index (CDAI), which can be found in the table below.

Table 2: Crohn’s Disease Activity Index (CDAI). See References.

Interpretation:

CDAI < 150 = clinical remission

CDAI 150-220 = mild Crohn’s disease

CDAI 220-450 = moderate to severe Crohn’s disease

CDAI > 450 = severe-fulminant disease

Mild-moderate disease

Inducing remission

The treatments differ for ileal and proximal disease, or diffuse colitis/disease involving the left colon. Budesonide is used as the first line for proximal disease, with prednisolone as an alternative.

Prednisolone is instead the first line for diffuse/left colonic disease, with aminosalicylates (5-ASAs) agents such as sulfasalazine considered as an alternative.

Maintenance

If steroids have successfully induced remission, then these should be tapered down, with a follow up colonoscopy in six to twelve months for monitoring.

For those treated with 5-ASA agents, these are recommended to be continued as long term maintenance, with a follow up colonoscopy.

Moderate-severe disease

Inducing remission

Corticosteroids still play an important role in short term induction and provide rapid symptom relief.

Patients with high risk features such as stricturating or perianal fistulating disease may warrant early consideration of biologics.

First line biologics can include anti-TNF agents such as infliximab, which may be given with an immunomodulator, e.g. 6-mercaptopurine (6-MP), azathioprine or methotrexate (TPMT genotype testing is recommended prior to commencement of therapy with azathioprine or 6-MP).

Alternative first line biologics include ustekinumab, an anti-IL-12/23 monoclonal antibody, which is indicated for patients who are biologic naive or refractory to standard therapy such as glucocorticoids, immunosuppressive agents, or anti-TNF agents. Vedolizumab is an anti-alpha-4-beta-7 (α4β7) integrin, and can be used for patients over the age of 60 or patients with a history of malignancy or infectious complications. Natalizumab is a humanised monoclonal antibody directed against alpha-4 integrin, but has limited use due to the potential for serious adverse events with particular concern for progressive multifocal leukoencephalopathy (PML).

Maintenance 

Immunomodulator therapy is a mainstay of maintenance therapy. This includes thiopurine therapy, Methotrexate and Mesalazine. There is also a role for anti-TNF, such as Infliximab and Adalimumab. Other biologic therapies include Vedolizumab, Ustekinumab

Severe-fulminant disease

Severe-fulminant Crohn’s disease is considered when symptoms are refractory to conventional therapy, or when complications such as intestinal obstruction, peritonitis or intra-abdominal abscess arise. Hospitalisation should be urgently arranged with prompt abdominal imaging and surgical consultation, if indicated.

In the context of an intraabdominal abscess, intravenous antibiotics, along with surgical or radiologically guided drainage, will be required.

If refractory to corticosteroid therapy or maintenance immunomodulatory therapy, biologic agents are considered.

Surgical management of Crohn’s disease

Failure to respond to medical treatment, severe acute disease, or complications may require surgical intervention – with key indications summarised below.

• Persistent inflammation causing intractable symptoms – may require surgical resection
• Bowel perforation
• Enteric fistula
• Intra-abdominal, retroperitoneal or abdominal wall abscesses – may require percutaneous or surgical drainage, with surgical excision of affected bowel segment
• Bowel obstruction – likely secondary to fibrosis or strictures, can be managed with endoscopic dilation, strictureplasty or surgical resection
• Enteric fistula refractory to medical management
• Small or large bowel cancer secondary to Crohn’s disease – requiring surgical excision or resection