TRPV1 and irritable bowel syndrome: When the IBS group was divided into symptom subgroups, there was no statistically significant difference in the numbers of TRPV1-immunoreactive fibres (IBS-D, n = 8, fibres/mm2, median 3.7, interquartile range 2.6–6.6; IBS-C, n = 7, 3.5, 2.1–4.9; and IBS-A, n = 8, 2.2, 2.0–5.2; ANOVA (analysis of variance) test, p = 0.23).