Ulcerative colitis (UC) is a chronic inflammatory condition of the large intestine (colon) and rectum, and one of the two main types of inflammatory bowel disease (IBD), alongside Crohn's disease.
Unlike Crohn's disease, UC is confined to the colon and rectum, always begins in the rectum, and spreads continuously up the bowel – it does not cause patchy or skip lesions elsewhere in the GI tract.
UC causes ulceration and inflammation of the inner lining of the colon. Symptoms tend to flare and remit over time. There is no medication-based cure, but surgery to remove the colon (colectomy) can be curative – an important distinction from Crohn's disease, where surgery does not eliminate the condition.
How common is Ulcerative Colitis?
Approximately 86,000 Australians are estimated to be living with ulcerative colitis. Like Crohn's disease, Australia has one of the highest rates of UC in the world. It is most commonly diagnosed between the ages of 15 and 40, though it can develop at any age, and affects men and women in roughly equal numbers.
Symptom severity varies depending on how much of the colon is affected.
Common symptoms include:
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- Bloody diarrhoea – one of the most characteristic features of UC
- Urgency to open the bowels, and frequent or urgent trips to the toilet
- Abdominal pain and cramping, typically in the lower left area
- Passing mucus with bowel motions
- Fatigue and low energy
- Unintended weight loss and reduced appetite
- Fever during active flares
- Feeling of incomplete bowel emptying (tenesmus)
In severe cases, UC can cause significant blood loss, dehydration, and electrolyte imbalance requiring hospitalisation. Like Crohn's disease, UC can also cause symptoms outside the gut, including joint pain, eye inflammation, and skin conditions.
The exact cause is not fully understood.
UC is thought to result from a combination of:
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- Genetics – UC runs in families; having a first-degree relative with IBD increases risk
- Immune system dysfunction – an abnormal immune response to gut bacteria triggers ongoing inflammation in the colon lining
- Environmental factors – including changes in gut microbiome, diet, and prior antibiotic use
Diagnosis involves a combination of:
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- Colonoscopy and biopsy – the primary diagnostic tool; allows direct visualisation of the colon lining and biopsy to confirm inflammation and rule out other causes
- Sigmoidoscopy – may be used when full colonoscopy is not immediately appropriate, particularly during a severe flare
- Blood tests – including inflammatory markers (CRP, ESR), full blood count, and nutritional assessments
- Stool tests – faecal calprotectin to assess gut inflammation, and stool cultures to exclude infection
- Imaging – CT or MRI may be used to assess disease extent or complications in severe cases
Treatment depends on disease extent (how much of the colon is affected) and severity. Goals are to induce and maintain remission and to heal the bowel lining.
Mild to moderate disease
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- Aminosalicylates (5-ASA) – such as mesalazine (Pentasa, Mezavant), are the mainstay of treatment for mild to moderate UC. Given orally, as an enema, or as a suppository depending on disease location. Effective for inducing and maintaining remission in mild disease
- Corticosteroids – used to quickly control active flares; not suitable for long-term maintenance
Moderate to severe disease
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- Immunomodulators – azathioprine and mercaptopurine are used to maintain remission in people who require more than aminosalicylates
- Biologic therapies — TNF inhibitors (adalimumab, infliximab), the anti-integrin vedolizumab, and the IL-12/23 inhibitor ustekinumab are options used at various stages of treatment when conventional therapies haven't provided adequate control.
- JAK inhibitors (Janus kinase inhibitors) — tofacitinib, upadacitinib, and filgotinib are oral targeted therapies used for moderate to severe UC.
- S1P receptor modulators — ozanimod is an oral targeted therapy used for moderately to severely active UC.
Surgery
Colectomy (surgical removal of the colon) may be necessary for people with severe or treatment-refractory UC, or in cases of complications such as toxic megacolon. Unlike Crohn's disease, surgery can be curative for UC.
The following specialty medications are available at Ace, a specialty pharmacy for Ulcerative Colitis.
Biosimilars of adalimumab and infliximab are available. Speak with your Ace pharmacist about your options.
Note: Aminosalicylates (e.g. mesalazine/Pentasa) are central to UC treatment but may not be stocked as specialty medications – confirm with your Ace pharmacist.
With Ace, you’ll benefit from:
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- Expert Support — Our dedicated team of health concierges is always available to answer your questions, provide guidance, and help you navigate your condition with confidence.
- Specialty Medication — We offer a wide range of specialty medications and support services, designed specifically for those living with chronic illnesses. Whether you’re looking for help managing a specific condition, or simply need access to the medications you need, we’ve got you covered.
- A Wide Range of Conditions — From diabetes to heart disease, and everything in between, we help manage a variety of special condition
Take control of your health and well-being, and start your journey to better health with Ace today.
IBD-Specific Support
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- Crohn's and Colitis Australia (CCA) – Australia's peak patient organisation for IBD; information, peer support, nurse helpline, and local support groups
- CCA – Nurse Helpline – 1800 CCA IBD (1800 222 423)
- CCA – Find a Doctor
Clinical & Research Resources
