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Inflammatory bowel diseases (IBD) are a group of diseases that brings about chronic inflammation to the digestive tract. They are chronic diseases because they last for a long time. Patients with inflammatory bowel diseases have high amounts of inflammation in the bowels. Crohn's disease and ulcerative colitis (UC) are the two main types of inflammatory bowel diseases. Approximately 1.6 million Americans suffer from IBD with 70,000 new cases of the diseases diagnosed each year. IBD can be diagnosed at any age although it is more likely to be seen in patients between the ages of 15 and 30. It also affects as many as 80,000 children in the US. Men and women are equally likely to develop IBD.  

Causes of IBD  

There are several factors that contribute to the development of IBD. Cause of the disease is an interaction between genetic, immune system, and environmental factors. A wide variety of genetic variations in multiple genes give rise to the development of IBD. Crucial is the inappropriate 'hyper-reactive' state of the immune system within the gut towards intestinal microbes. Scientific research has identified over 160 genes associated with IBD. Having a parent who has IBD puts the child at greater risk of developing the disease as compared to the general population.

However, the exact cause of inflammatory bowel disease is not known and still under research. In the past decade we have reached major scientific advances in understanding the underlying mechanisms involved in IBD, this helps expand the potential effective treatment options for different types of IBD cases.   

Pie chart depicting different causes of IBD: Genes, Microbes & Immune System
Image of different areas of the intestines that are affected by Crohn's Disease & Ulcerative Colitis

IBD symptoms

When the digestive tract is chronically inflamed, it produces symptoms such as diarrhea, abdominal cramps and pain, bloody stools and the formation of ulcers. Patients may also experience symptoms such as fever, loss of appetite, fatigue and weight loss. Symptoms of inflammatory bowel disease will vary from patients to patients as well as change over time.  

Complications of IBD  

Chronic inflammation in the digestive tract can also result in complications within and outside of the digestive tract. Within the gastrointestinal tract, complications include abscesses, fistulas, holes in the digestive tract or perforations, malabsorption and nutritional deficiencies. Common complications outside of the digestive tract (extraintestinal manifestations) include osteoporosis of the bones, inflammation of the eyes, joints, mouth and skin, kidney stones and sclerosing cholangitis.

Ulcerative colitis vs Crohn's disease

Crohn's disease is a chronic inflammation of any part of the gastrointestinal tract. More about Crohn's disease

Ulcerative colitis, one of the two main forms of IBD, affects the large intestine or the colon. More about ulcerative colitis