There are six main risk factors for developing inflammatory bowel disease, according to healthline.com. Some are within our control, but most are not. 1. Age: Age seems to be an important factor when it comes to the development of inflammatory bowel disease. In most cases of IBD, the symptoms begin before a person reaches 35. 2. Ethnicity: Certain ethnic groups are more predisposed to inflammatory bowel disease. In particular, Caucasians and Ashkenazi Jews. 3. Geographic region: While this is controllable to a certain extent, in reality, most people cannot simply move to places where the prevalence of IBD is low. Unsurprisingly, urban and industrial areas have a higher prevalence than rural and unindustrialized areas. The further north you live also has a bearing on risk, as IBD prefers colder climates. Those who live in urban areas are also more likely to consume processed foods which doesn't help. MORE: What it's like growing up with inflammatory bowel disease 4. Gender: While both males and females are susceptible to inflammatory bowel disease, males are more likely to have ulcerative colitis while women are more likely to have Crohn's disease. 5. Family history of IBD: IBD tends to run in families. If you have a close relative with either Crohn's disease or ulcerative colitis your chances for IBD are increased. 6. Smoking: Smoking is the only main risk factor that is truly controllable for Crohn's disease. Conversely, ex-smokers are more likely to be affected by ulcerative colitis — so the message here is not to smoke in the first place.