The patterns of inflammation and collagen deposition differ between Crohn's disease (CD) and ulcerative colitis (UC). Assuming that both processes alter the mechanical properties of the bowel wall, its stiffness is a potential discriminatory feature between the two diseases. The aim of this study was to determine whether is it possible to differentiate between active Crohn's colitis, with rectal involvement, and active ulcerative colitis, on the grounds of pseudoquantitative measurements obtained by transrectal ultrasound-guided strain elastography. 28 CD patients, 30 UC patients and 30 controls were enrolled in the study. Regions of interest were placed over the rectal wall and the adjacent perirectal tissue. Relative strain and average Histogram values were measured in every region and Strain Ratio (SR) and Histogram Ratio (HR) were calculated. There were no statistically significant differences in SR and HR between the three groups. The relative rectal wall strain was lower in CB group compared to UC group (P=0,035), average rectal wall Histogram value was higher in CB group compared to UC group but the difference did not reach statistical significance (P=0,067). According to our results, SR and HR measurements do not discriminate between UC and CB, however, relative strain differences between the two groups suggest that strain elastography might have a role in inflammatory bowel disease diagnostics.