KIT and irritable bowel syndrome: There was no increased or decreased mast cell number in biopsies from the duodenum, proximal colon (c-kit: p = 0.456, tryp: p = 0.534), distal colon (c-kit: p = 0.747, tryp: p = 0.551) or rectum (c-kit: p = 0.515, p = 0.596) of IBS-D and MC-D patients compared to non-IBS/non-MC (duodenum c-kit: p > 0.05; tryp: p > 0.05; prox.