Table 1.

Patient characteristics in study group (mean ± SE)

	IBS	Healthy	P*
No of subjects	100	100
Female: Male ratio	73:27	70:30	NS
Age (yr)	48 ± 2	45 ± 2	NS
BMI (Kg/m2)	23.5 ± 0.4	22.9 ± 0.3	NS
Coffee-drinkers No (%)
None	43 (43%)	24 (24%)	0.03°
< 1 per day	9 (9%)	22 (22%)°
1-5 per day	48 (48%)	54 (54%)°
Smokers No (%)	30 (30%)	15 (15%)	0.02°
Lower abdominal	5.8 ± 0.1	0.04 ± 0.01	0.0001
pain (VAS, cm)
Abdominal bloating	6.2 ± 0.1	0.1 ± 0.02	0.0001
(VAS, cm)

*Student’s t test or χ² for comparison of proportions, VAS = visual analogue scale.