Increased expression of brain-derived neurotrophic factor is correlated with visceral hypersensitivity in patients with diarrhea-predominant irritable bowel syndrome

Figure 1 Visceral sensitivity parameters in patients with diarrhea-predominant irritable bowel syndrome and healthy controls. A: The first sensation threshold was not significantly different between the two groups (P = 0.084); B: The defecating sensation threshold was significantly lower in diarrhea-predominant irritable bowel syndrome (IBS-D) patients than in controls (P = 0.009); C: The maximum tolerable threshold was significantly decreased in the patients (P < 0.001); D: The rectoanal inhibitory reflex threshold was also significantly lower in IBS-D patients (P = 0.032). Each set of data is presented as box-whisker plot or scatter plot. Boxes indicate the interquartile range; lines inside the boxes indicate the medians (the median lines and the edges of the boxes of plot D overlap); the two whiskers indicate the maximum and minimum of the data; and the lines in the scatter plots indicate the mean values. RAIR: Rectoanal inhibitory reflex; IBS-D: Diarrhea-predominant irritable bowel syndrome.