Genetic links found to bowel disease
Researchers linked 29 DNA regions with ulcerative colitis, a form of IBD affecting the lower intestine.
The findings support the theory that an immune reaction to natural bacteria in the gut may play a role in the condition.
Scientists hope the new discoveries will open the door to further research and new treatments.
Richard Driscoll, chief executive of the charity Crohn's and Colitis UK, said: "This research will give renewed hope to the 160,000 people in the UK who face a lifetime coping with ulcerative colitis.
"The illness tends to flare up quite unpredictably and without apparent cause, and at these times the symptoms of urgent diarrhoea, pain and fatigue can dominate everyday life and may eventually lead to major surgery.
"Knowing that researchers have identified specific new targets for research and that progress is being made will be seen as very good news."
Ulcerative colitis and Crohn's disease are the primary causes of IBD, affecting one in 250 people in Europe and North America.