Crohn's disease can be an inflammatory bowel disease (IBD) that can cause severe abdominal pain, diarrhoea, weight reduction, and fatigue. It is a chronic condition that can lead to serious complications and even death if left untreated. The exact cause of Crohn's disease is unknown, though it's thought to be attributable to a blend of genetic and environmental factors. There isn't a cure for Crohn's disease, but there are treatments that may also help control symptoms and stop further damage as well as the intestines.