Phenotypic Variation in Functional Disorders of Defecation Adil E. Bharucha, Joel G. Fletcher, Barb Seide, Stephen J. Riederer, Alan R. Zinsmeister  Gastroenterology  Volume 128, Issue 5, Pages 1199-1210 (May 2005) DOI: 10.1053/j.gastro.2005.03.021 Copyright © 2005 American Gastroenterological Association Terms and Conditions

Figure 1 Sagittal dynamic MRI images of (left panel) normal puborectalis relaxation (subject 1) and (right panel) puborectalis contraction (arrow; subject 2) during rectal evacuation. In both subjects, evacuation was associated with perineal descent (2.6 cm in subject 1; 1.7 cm in subject 2) and opening of the anorectal junction. During evacuation, the anorectal angle increased by 36° in subject 1 and declined by 10° in subject 2. Gastroenterology 2005 128, 1199-1210DOI: (10.1053/j.gastro.2005.03.021) Copyright © 2005 American Gastroenterological Association Terms and Conditions

Figure 2 Comparison of change in (A) anorectal angle and perineal descent during rectal evacuation in controls and (B) location of anorectal junction at rest relative to the pubococcygeal line in controls. Gastroenterology 2005 128, 1199-1210DOI: (10.1053/j.gastro.2005.03.021) Copyright © 2005 American Gastroenterological Association Terms and Conditions

Figure 3 Variations in anorectal and pelvic floor motion during evacuation in patients. (A) The pelvic floor was immobile during squeeze and evacuation. The anterior abdominal wall moved outward during evacuation, suggesting increased intra-abdominal pressure. (B) The puborectalis (white arrow) not only impeded evacuation but also perhaps precluded effective force transmission to the rectal segment above the anorectal junction. Observe the out-pouching of the anterior rectal wall or perhaps the anal canal (black arrow). (C) A patient in whom the anorectal junction was relatively low (ie, 2.5 cm below the pubococcygeal line) at rest, declining to 5.6 cm below this line during defecation. Despite normal descent and opening of the anorectal angle, only 5% of the rectal contents were expelled. (D) Excessive perineal descent during evacuation associated with a rectocele (arrow). Gastroenterology 2005 128, 1199-1210DOI: (10.1053/j.gastro.2005.03.021) Copyright © 2005 American Gastroenterological Association Terms and Conditions

Figure 4 Correlation between variables and (A) factors 1 and 2 and (B) factors 2 and 3. These plots incorporate the 7 response variables incorporated in the principal components analysis (which are demarcated by square boxes) and other measured parameters. The correlation reflects the contribution of a given variable to a factor, that is, a higher correlation (maximum = 1) suggests a greater contribution of the variable to that principal component. The parameters were assessed by MRI (angle measurements are in open circles, and anorectal junction motion is shown as filled circles), anal manometry and rectal balloon expulsion (open squares), and rectal sensation (open triangles). The legend for parameters that had the highest weighting (positive or negative) in each score is in bold. Ang, angle; Loc, location; Des, perineal motion (ie, ascent or descent of anorectal junction relative to pubococcygeal line); AP, anteroposterior motion; Re, Rest; Sq, squeeze; Def, defecation; Bal Exp, balloon expulsion; Pr, pressure. For example, DesReSq indicates perineal motion during squeeze relative to at rest. Gastroenterology 2005 128, 1199-1210DOI: (10.1053/j.gastro.2005.03.021) Copyright © 2005 American Gastroenterological Association Terms and Conditions

Figure 5 Distribution of principal component (PC) scores (A) 1 and 2 and (B) 1 and 3 in controls and patients. For each subject, the principal component scores were derived by summing the product of the loading for a parameter (shown in Table 3) and the value for that parameter for all 7 variables. A shows that a PC 1 score of −0.81, represented by a line parallel to the y-axis, discriminated controls from 17 of 18 patients with reduced perineal descent. The PC 2 score ranged from −2.1 to 3.1 in controls. This score did not discriminate between patients and controls. For PC 3, a score of 0.75, represented by the line parallel to the x-axis, separated 40 of 42 controls (with a PC 3 score <0.75, ie, situated below this line) from 16 patients. Gastroenterology 2005 128, 1199-1210DOI: (10.1053/j.gastro.2005.03.021) Copyright © 2005 American Gastroenterological Association Terms and Conditions