Type 1:	Here, the patient can generate an adequate pushing force, (rise in intra abdominal pressure) along with a paradoxical increase in anal sphincter pressure (Fig. 2).
Type 2:	Here, the patient is unable to generate an adequate pushing force (no increase in intrarectal pressure) but can exhibit a paradoxical anal contraction (Fig. 2).
Type 3:	Here, the patient can generate an adequate pushing force (increase in intrarectal pressure) but, either has absent or incomplete (<20%) sphincter relaxation (i.e. no decrease in anal sphincter pressure) (Fig. 2).
Type 4:	The patient is unable to generate an adequate pushing force and demonstrates an absent or incomplete anal sphincter relaxation (Fig. 2).