Altered profiles of fecal metabolites correlate with visceral hypersensitivity and may contribute to symptom severity of diarrhea-predominant irritable bowel syndrome

Figure 1 Visceral sensation thresholds to rectal distension stimulation. A: The first sensation threshold showed no significant difference between the two groups (P = 0.315). B: The score of the defecating sensation threshold was significantly decreased in the patients (P = 0.032). C: The maximum tolerable threshold was also lower in patients with irritable bowel syndrome with predominant diarrhea than in controls (P < 0.001). Box means the interquartile range; line inside the boxes indicates the median; the two whiskers indicate the 5^th percentile and 95^th percentile of the data. ^aP < 0.05 vs healthy control (HC); ^bP < 0.01 vs HC. IBS-D: Irritable bowel syndrome with predominant diarrhea; HC: Healthy control.