Restricted Fetal Growth Increases Risk Of Irritable Bowel Syndrome

The Norwegian authors base their findings on 3334 twin pairs, 1250 of whom were identical. The twins completed a comprehensive questionnaire about their health, including whether they had ever had IBS.

This information was then matched with weight at birth, supplied by the national twin registry and divided into four groups, ranging from less than 1500 g to more than 2500 g. A healthy birthweight is considered to be above 2500 g.

The rate of IBS across the entire sample was 5.4%, roughly one in 20. But there was a significant gender difference: the rate in men was 3%, while that in women was 7%.

There was little difference, however, in the average age of onset between the two sexes. The first signs of the condition appeared at the age of 18 in men, and a year earlier in women.

Only one in four of those who reported IBS symptoms at some point in their lives, were symptom free at the time of the survey, and the average duration of their symptoms was more than 4.5 years.

The likelihood of IBS was stronger among the identical twins, suggesting that genetic factors do play a part, say the authors.

But the risk of the condition was 2.5 times greater among those whose birthweights were below 1500 g as it was among those weighing more than 2500 g at birth. And it was higher in the lower weight baby of the twin pair.

The age at which symptoms started also seemed to be associated with birthweight. Those weighing in at less than 1500 g at birth were, on average, likely to develop IBS more than 7 years earlier than those weighing over 1500 g.

The authors point out that several chronic diseases have been linked to low birthweight, and that the healthy development of the digestive system, which is not complete at birth, could be hindered by insufficient fetal growth.