Inflammatory Bowel Disease (IBD) is a collective term for two chronic, autoimmune diseases of the gastrointestinal tract: ulcerative colitis (UC) and Crohn’s disease (CD). UC causes inflammation and ulceration of the mucosa of the bowel and rectum, resulting in symptoms including abdominal pain and diarrhoea^[1]. CD typically causes transmural inflammation of any part of the gastrointestinal tract^[8]. 

Common symptoms of IBD include^[1,7]: 

• Mucus and/or blood in the stool
• The need to open bowels urgently
• Fatigue
• Reduced appetite
• Weight loss 
• Fever
• Anaemia 

It is estimated that IBD currently affects 0.3% of the global population, which is cause for concern^[6]. A cross-sectional study published in 2021 analysed general practice data from 2017-2019 and found an estimated IBD prevalence of 653 per 100,000 patients in Australia^[9]. A person may develop IBD at any time in their life, however it most commonly presents first between the ages of 15-30 years old^[1]. The disease may also fluctuate over time as symptoms can flare up and then go into remission for periods^[2].

Causes of IBD

Current research suggests that IBD is caused by a combination of genetic, microbiota, environmental, mucosal, and systemic immune factors. There are more than 200 single nucleotide polymorphisms associated with IBD, with many different potential contributions to disease. Potential microbiota associations with IBD include the presence/absence of pro-inflammatory bacteria and even specific bacterial species. When considering environmental associations with IBD, different diets have not been shown to significantly impact the risk of developing the disease. Rather, lifestyle and living conditions in childhood may have an association with an increased risk of developing IBD. Immunological causes of IBD may include the innate and adaptive immune response to various pathogens^[3].

Complications of IBD

UC/CD may result in^{[4, 10]}:

• Severe blood loss
• Severe dehydration 
• Swollen/ perforated colon
• Thrombosis
• Osteoporosis
• Inflammation of skin, joints, and eyes
• Fibrosis and strictures of the bowel (CD only)
• Increased risk of lymphoma
• Increased risk of colorectal cancer 

Currently approved treatments

Whilst there is currently no cure for IBD, there are numerous management strategies including medication, surgery, and lifestyle changes. Some medications used to treat both IBD include: Aminosalicylates, corticosteroids, immunosuppressants, antibiotics and biologics^[5]. Janus kinase inhibitors have shown to be successful in managing UC but not CD^[11]. These medications act in different ways to reduce the inflammation caused by IBD^[5]. In instances where the bowel has been irreversibly damaged by IBD, an ileostomy or pouch surgery may be required.

If you want more details about running IBD clinical trials in Australia, get in touch with us today.

Continue on to part 2 of this series on running IBD trials which includes study design considerations.

References

1. https://www.healthdirect.gov.au/ulcerative-colitis 
2. https://crohnsandcolitis.org.au/about-crohns-colitis/ulcerative-colitis/about-ulcerative-colitis/  
3. https://onlinelibrary.wiley.com/doi/full/10.1002/jgh3.12216 
4. https://www.mayoclinic.org/diseases-conditions/ulcerative-colitis/symptoms-causes/syc-20353326 
5. https://crohnsandcolitis.org.au/about-crohns-colitis/ulcerative-colitis/ulcerative-colitis-treatment/ 
6. https://link.springer.com/article/10.1007/s12664-023-01453-6#:~:text=Inflammatory%20bowel%20disease%20(IBD)%20has,the%20world%20population%20%5B1%5D. 
7. https://www.hopkinsmedicine.org/health/conditions-and-diseases/crohns-disease
8. https://journals.lww.com/ajg/fulltext/2011/04001/An_Evidence_Based_Systematic_Review_on_Medical.2.aspx 
9. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8158877/ 
10. https://academic.oup.com/ibdjournal/article/17/1/471/4631202 
11. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8582842/#:~:text=Janus%20kinase%20inhibitors%20are%20small-molecule%20drugs%20that%20can,less%20effective%20in%20those%20with%20Crohn%E2%80%99s%20disease%20%28CD%29