Crohn’s disease is one of two similar forms of chronic inflammatory disease. The other is ulcerative colitis. Crohn’s disease usually affects the small bowel, and rarely, the large bowel. There are times of symptom-free remission, but also active periods with pain in the abdomen, diarrhoea and weight loss that can be so severe that people cannot go to work or undertake their daily activities. Attacks can be so severe that people need to go to hospital.