Table 1. Demographics, IBS symptom severity, and psychological distress scales.

	Controls	IBS total	IBS-D	IBS-C	IBS-M	IBS-U¶
Number	30	129	44	29	45	11
Female n. %)	22 (73)	109 (84)	34 (77)	26 (90)	38 (84)	11 (100)
Age (yr)	37.2±2.2	35.8±1.1	36.6±2.0	34.9±2.0	35.1±1.9	38.4±3.5
Race
White	13	90	31	16	37	6
Non-white	14	36	12	12	7	5
Unknown	3	3	1	1	1	0
IBS-SS
Overall	27.9±9.8	273.2±8.1**	255.8±15.1**	281.1±16.5**	282.2±13.6**	287.9±13.2
Pain Severity	4.7±2.4	47.0±2.2**	43.3±3.8**	45.5±4.5**	48.2±3.9**	64.4±5.6
Pain Frequency	4.5±2.3	47.2±2.1**	43.4±3.6**	46.6±4.5**	48.9±3.7**	58.9±5.1
Distention	3.3±1.5	44.8±2.6**	38.5±4.7**	51.4±5.3**	48.4±4.1**	35.7±8.8
Bowel Dissatisfaction	18.0±5.8	77.6±2.2**	72.9±4.3**	80.7±4.0**	80.7±3.2**	75.0±9.1
QOL	2.7±1.9	56.4±2.6**	57.2±4.6**	56.9±5.3**	55.9±4.1**	53.9±11.0
BSI-18
Global Scale	42.3±1.5	52.4±0.8**	53.4±1.5**	51.6±1.6**	52.5±1.2**	49.8±3.6
Somatization	44.8±1.2	54.1±0.7**	55.5±1.1**	52.8±1.6**	53.9±1.0**	52.9±3.4
Depression	46.0±1.5	51.0±1.0*	52.6±1.9**	52.0±1.8*	49.4±1.6	49.0±5.1
Anxiety	43.3±1.2	51.1±0.8**	51.7±1.4**	50.6±1.7**	51.8±1.4**	45.8±2.6

Note.

^¶No statistical comparisons were made to the IBS-U group because of a small sample size. Data were shown as mean ± SEM.

^*p<0.05,

^**p<0.01, compared with controls, Mann-Whitney U test. IBS-SS: IBS severity scale, BSI-18: Brief Symptom Index 18.