Table 1. Studies included in the meta-analysis.

Study	Modality	Subjects	Supraliminal rectal inflation conditions
Berman et al. (2000)23	PET	Study 1: 13 (7 F) IBS	20, 45 and 60 mmHg
		Study 2: 17 (6 F) IBS
Hobday et al (2001)27	fMRI	8 M Controls	average 11 p.s.i.
Lotze et al (2001)30	fMRI	8 Controls (4 F)	average 173.6ml
Naliboff et al (2001)13	PET	12 (2 F) IBS	45 mmHg
		12 (2 F) Controls
Bonaz et al (2002)25	fMRI	11 (10 F) IBS	individually determined maximum tolerable volume
Verne et al (2003)36	fMRI	9 (6 F) IBS	55 mmHg
		9 (6 F) Controls
Naliboff et al (2003)32	PET	42 (23 F) IBS	45 mmHg
Andresen et al (2005)22	fMRI	8 (3 F) Controls	individually determined perception threshold +10 mmHg
		8 (5 F) IBS
Kwan et al (2005)29	fMRI	11 (7 F) Controls	individually determined moderate pain
		9 (6 F) IBS
Berman et al (2006)24	fMRI	13 (6 F) Controls	25 and 45 mmHg
Naliboff et al (2006)33	PET	12 (8 F) IBS	45 and 60 mmHg
Song et al (2006)35	fMRI	12 F IBS	pain detection +20%
		12 F Controls
Price et al (2007)34	fMRI	9 IBS	individually determined moderate pain (rating of 40 out of 100)
Berman et al (2008)7	fMRI	14 F IBS	25 and 45 mmHg
		12 F Controls
Ringel et al (2008)4	fMRI	10 F Controls	15 and 50 mmHg
		10 F IBS
Elsenbruch et al (2009)26	fMRI	15 F IBS	individually determined discomfort level
		12 F Controls
Kanazawa et al (2010)28	PET	32 M Controls	20 and 40 mmHg
Moisset et al (2010)31	fMRI	11 F Controls	individually determined non-painful sensation and moderate pain
		M: Male; F: Female