The research focused on two national groups of people born in 1958 and 1970 in Great Britain, who were monitored by questionnaire at the ages of 26 and 33.
Handedness was determined from hand preference for writing and foot preference for kicking a ball, at the age of either 7 or 10.
In total, around 17,000 people were included in the study.
Significantly more men than women were left-handers, but gender was not itself associated with increased risk of inflammatory bowel disease (IBD).
However, later birth was associated with a heightened risk. Those born in 1970 were more likely to have IBD than those born in 1958.
|Left-handedness is associated with autoimmune disease.|
Altogether, 71 people had either confirmed Crohn's disease or ulcerative colitis. Left-handers were more than twice as likely to be affected overall.
A similar pattern was found for Crohn's disease and ulcerative colitis, when both the diseases were looked at separately.
Left-handedness has been linked with various autoimmune diseases, including asthma, migraine, autism, and diabetes. However, so far no one has been able to pinpoint why.
Dr Danielle Morris, of the Royal Free Hospital, London, and fellow authors point to previous research showing a seasonal variation in the birth of left-handed girls. They say that this might implicate some environmental factor.
Another somewhat controversial explanation is the amount of testosterone a fetus is exposed to in the womb, which may affect brain and immune system development.