Objective. Patients with ulcerative colitis in remission (UCR) frequently report irritable bowel syndrome (IBS)-like symptoms. Recent studies have pointed to the role of mast cells in mediating... Show moreObjective. Patients with ulcerative colitis in remission (UCR) frequently report irritable bowel syndrome (IBS)-like symptoms. Recent studies have pointed to the role of mast cells in mediating visceral hypersensitivity in IBS. We hypothesized that visceral hypersensitivity is frequently present in patients with UCR and is related to the quantity and activity of mast cells in the sigmoid mucosa. Material and methods. A group of 17 controls and 19 patients with UCR were studied. Rectal compliance and perception were measured by electronic barostat. Sigmoid biopsies were taken to quantify the amount of mast cells, degranulating mast cells and mast cells in close proximity to mucosal nerve endings. Results. Visceroperception significantly increased in UCR (p < 0.05) versus controls. Rectal perception correlated positively with IBS-like symptoms in UCR (r = 0.969; p < 0.05). The amount of mucosal mast cells (per 100 crypts) was significantly increased in UCR versus controls: 228 perpendicular to 20 versus 163 perpendicular to 18 (p < 0.05). In the UCR patients a higher percentage of mucosal mast cells was in close proximity to nerve endings (58 +/- 4 vs. 38 +/- 3% in controls; p < 0.05) or was degranulating (40 +/- 7 vs. 16 +/- 4% in controls; p < 0.05). There was a significant but weak correlation between quantity of mucosal mast cells and pain perception (r = 0.32; p < 0.05). Conclusion. Rectal hypersensitivity is associated with mucosal presence and activation of mast cells and with IBS-like symptoms in patients with UCR. Show less
