Fig. 3.

Radiologic image illustrating changes in the anorectum during gradual filling of rectal balloon in one subject. The puborectal pressure increases (a) during gradual filling of the rectal balloon (a), while the anal canal rotates in the direction of the pubic bone (b–f). The angle made by the dotted green line of anal canal at the start of the test and by the shifting line of anal canal observed during the gradual filling of the rectal balloon (continuous green line) was increasing at different stages of the measurements (b–f), i.e., at first sensation (FS), constant sensation (CS), urge sensation (US), and maximum tolerable sensation (MTS)