Figure 3  .

Numbers of mast cells in colonic strictures in Crohn's disease compared with normal colon. Mast cells were detected by staining for tryptase and chymase. Mast cell numbers were determined in five adjacent microscope fields in the mucosa, submucosa, and muscularis propria at 200 × magnification and normalised to 1 mm². Mast cell numbers for the three different bowel compartments of strictured colon of Crohn's disease were compared with those of the respective compartments of normal colon: †p<0.005, ‡p<0.0005,**p<0.01.