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Overview and prevalence

Inflammatory bowel disease (IBD) is characterised by chronic inflammation of the gastrointestinal tract and is an umbrella term used to describe Crohn’s disease and ulcerative colitis (NHS, 2020). The prevalence of IBD has been found to be highest in Europe and North America, although the incidence has also been rising in newly westernised countries in South America, Asia, and Africa (Ng et al, 2018). Crohn’s disease is a chronic inflammatory trans-mural inflammation, meaning it affects all layers of the intestinal mucosa, and this contrasts with ulcerative colitis which is limited to the mucosa (Qin, 2013). Otherwise, ulcerative colitis is defined as a chronic inflammatory disease of the colon (Ungaro et al, 2016). Both Crohn’s disease and ulcerative colitis are long term inflammations of the gastrointestinal tract, however Crohn’s disease affects the entire digestive system whilst ulcerative colitis is limited to the large intestine/colon (NHS, 2020). Males and females are affected equally in IBD. The peak onset for Crohn’s disease however is between 20 and 30 years of age whilst ulcerative colitis has a bimodal onset of between 20 and 30 years of age and also at 50 years of age. 


Symptoms of ulcerative colitis relate to the underlying inflammation, whereby small ulcers develop along the lining of the colon (NHS, 2019). This causes frequent diarrhoea, abdominal pain, fatigue, weight loss and the urge to go to the toilet (NHS, 2019). Crohn’s disease has similar symptoms in addition to fever, nausea, joint pains, rectal bleeding, and mouth ulcers (NHS, 2021). The symptoms are not constant for both diseases, as periods of flare ups and remission will occur. 


There is currently no cure for IBD, and treatment instead aims to reduce symptoms and reduce their reoccurrence (NHS, 2020). Firstly, IBD needs to be diagnosed and an endoscopy is normally performed alongside blood tests to examine specific biomarkers (Kilcoyne et al, 2016). The endoscopy enables the visualisation of the gastrointestinal tract and biopsies can be taken which compare the affected and non-affected mucosa (Spiceland et al, 2018). The first line treatment is the use of steroids such as prednisolone which work by reducing the inflammation in the digestive system (NHS, 2021). If steroids have little impact, then immunosuppressants may also be trialled such as methotrexate which lowers the activity of the immune system and can be used as a long-term treatment to prevent flare ups (NHS, 2021). The worst-case scenario for both Crohn’s disease and ulcerative colitis is a surgery which sees the removal of the affected parts of the digestive system (NHS, 2021). 

If you experience symptoms of IBD it is important to speak to a doctor as soon as possible to prevent any associated complications. Otherwise, IBD can be managed well and there is plenty of support and further information available via doctors, dietitians and on the internet. If you’re interested in learning about other nutrition related topics, then take a further look at the Nutritank blog. 


Kilcoyne, A., Kaplan, J.L., Gee, M.S. (2016). Inflammatory bowel disease imaging: current practice and future directions. World Journal of Gastroenterology 22(3): pp. 917-932. 

Ng, S.C., Shi, H.Y., Hamidi, N., Underwood, F.E., Tang, W., Benchimol, E.I., Panaccione, R., Ghosh, S., Wu, J.C.Y., Chan, F.K.L., Sung, J.J.Y., Kaplan, G.G. (2018). Worldwide incidence and prevalence of inflammatory bowel disease in the 21st century: a systematic review of population-based studies. The Lancet 390(10114): pp. 2769-2778. 

NHS (2021). Crohn’s Disease. [Online]. Available from:’s%20disease,they’re%20given%20as%20injections[Accessed 27/09/22].

NHS (2020). Inflammatory bowel disease. [Online]. Available from: [Accessed 27/09/22].

NHS (2019). Ulcerative Colitis. [Online] Available from: [Accessed 27/09/22]. 

Qin (2013). Why is damage limited to the mucosa in ulcerative colitis but transmural in Crohn’s disease? World Journal of Gastrointestinal Pathophysiology. 4(3): pp. 63-64. 

Spiceland, C.M., Lodhia, N. (2018). Endoscopy in inflammatory bowel disease: role in diagnosis, management, and treatment. World Journal of Gastroenterology 24(35): pp. 4014-4020. 

Ungaro, R., Mehandru, S., Allen, P.B., Peyrin-Biroulet, L., Colombel, J.F. (2016). Ulcerative Colitis. The Lancet 389(10080): pp. 1756-1770. 

Charlotte Ripley

My name is Charlotte and I'm a currently doing a Masters in Dietetics at King's College London. As part of my public health placement, I'm working with Nutritank. So far it has involved looking into partnerships with different organisations and reviewing and writing different nutrition pieces for some of Nutritank's current partnerships and for the blog. It's great to meet such a welcoming team of nutritionists, dietitians and medics, and to get involved with an organisation with such an important mission! I completed my Nutrition BSc at Newcastle University before deciding I wanted to pursue a career as a dietitian. Upon completion of the masters, I'm hoping to start as a band 5 dietitian in the NHS. I'm hugely interested in gastroenterology, including IBS, IBD and weight management. I'm very outdoor-sy and in my spare time I love running, long walks and spending time with friends. As a student living in London, there's also always exciting things happening to get involved with.