Serotonin receptor 2B induces visceral hyperalgesia in rat model and patients with diarrhea-predominant irritable bowel syndrome

Figure 2 Validation of the establishment of an irritable bowel syndrome with diarrhea rat model. A: The irritable bowel syndrome with diarrhea (IBS-D) group had higher abdominal withdrawal reflex scores than did the normal control group, with colorectal distension pressures of 30, 45 and 60 mmHg but not 15 mmHg; B: The IBS-D group also had a decreased threshold pressure compared with that of the normal control group; C: The water content of the feces in the IBS-D group and normal control group; D: The weight of fecal pellets in the IBS-D group and normal control group; E: Inflammation evaluation of the colon in IBS-D rats and normal control rats using hematoxylin and eosin stain. No significant inflammation or abnormalities in structure were observed in IBS-D rats or normal control rats. Magnification 20 ×; ^aP < 0.05, ^bP < 0.01, ^cP < 0.001. IBS-D: Irritable bowel syndrome with diarrhea; HE: Hematoxylin and eosin; AWR: Abdominal withdrawal reflex.