Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Dec;9(24):e15144.
doi: 10.14814/phy2.15144.

Differences in fatigability of muscles involved in fecal continence: Potential clinical ramifications

Krupa Patel  1 , Ling Mei  1 , Elliot Yu  1 , Mark Kern  1 , Navjit Lehal  1 , Francis Edeani  1 , Patrick Sanvanson  1 , Emily R W Davidson  2 , Reza Shaker  1
Affiliations

Differences in fatigability of muscles involved in fecal continence: Potential clinical ramifications

Krupa Patel et al. Physiol Rep. 2021 Dec.

Abstract

Introduction: Fatigue of the anal sphincter complex has been demonstrated using high-resolution anorectal manometry (HRAM). However, the fatigability of individual muscles such as the external anal sphincter (EAS) and puborectalis muscles (PRM) has not been described. Vaginal manometry has been used to study contractile activity of the PRM. By applying both modalities, we attempted to differentiate the fatigability between the PRM and the EAS under different exercise conditions.

Methods: We studied two groups: group 1, 12 healthy women (21 ± 2.7 years) with HRAM and group 2, 10 healthy (20 ± 3 years) women with vaginal manometry. All subjects performed 40 repetitive contractions with and without an intra-anal resistive load. In group 1, areas under the curve (AUC) of the anal canal high-pressure zone (HPZ) including the caudal and rostral halves were compared. In group 2, the maximum and mean pressures of the vaginal HPZ were compared.

Results: The AUC decreased significantly only after repetitive contractions against a resistive load (462 ± 129 vs. 390 ± 131 mmHg-cm, p = 0.02), indicating fatigue. The caudal half (EAS) decreased significantly after contractions against a load (288 ± 75 vs. 239 ± 82 mmHg-cm, p = 0.02), while the rostral half (PRM) did not. The vaginal pressures (PRM) also decreased only after repetitive contractions against a load (maximum pressures, 358 ± 171 vs. 239 ± 109 mmHg, p = 0.02).

Conclusions: The EAS and PRM both exhibit fatigue with contractions only against a resistive load. These findings may guide the development of appropriate exercise regimens to target specific muscles involved in fecal continence.

Keywords: anorectal manometry; external anal sphincter; fecal incontinence; puborectalis muscle; vaginal manometry.

PubMed Disclaimer

Conflict of interest statement

The authors report no financial or personal conflict of interest.

Figures

FIGURE 1
FIGURE 1
The continence muscles Resistance Exerciser Device along with a cartoon description of the device with the manometry catheter in the anal canal
FIGURE 2
FIGURE 2
ManoView software showing a contraction on anorectal manometry by topographical color plot
FIGURE 3
FIGURE 3
A sample patient squeeze and resting curve at a single time point during anorectal manometry. The x‐axis depicts the channel along the anal canal, where 1 is the channel most caudal within the anal canal. The y‐axis is the pressure values measured at each channel
FIGURE 4
FIGURE 4
Total area under the curve (mmHg‐cm) during anorectal manometry for the resting state, contractions without a load, and contractions against a load for both the first five and last five contractions (±SD). * indicates statistical significance at p < 0.05 when comparing the first five to the last five contractions against a load using a paired t‐test. This indicates fatigue. There is no statistical difference when comparing the first five to last five contractions without a load. n = 12 subjects
FIGURE 5
FIGURE 5
Caudal and rostral halves of area under the curve (AUC) during anorectal manometry for the resting state, contractions without a load, and contractions against a load for both the first five and last five contractions (±SD). * indicates statistical significance at p < 0.05 when comparing the rostral and caudal AUC halves using a paired t‐test. There is a significant difference between the rostral and caudal halves during contractions in all exercise settings. There is also a significant difference when comparing the caudal AUC for the first five to the last five contractions. n = 12 subjects
FIGURE 6
FIGURE 6
Change in maximum squeeze pressure (Max ± SD) in vaginal HPZ over 40 repetitive anal squeeze contractions, no load versus with load. The y‐axis is the maximum squeeze pressure (mmHg) and the x‐axis is the order of contractions, which are grouped into eight epochs. Repetitive short squeeze contractions against a load showed significant decrease in maximum squeeze pressure in vaginal HPZ. Linear regression analysis showed a significant negative correlation between maximum squeeze pressure and successive squeeze exercise against a load. There is no significant change in maximum squeeze pressure during exercise without load. n = 10 subjects
See this image and copyright information in PMC

References

    1. Agrawal, D. , Kern, M. , Edeani, F. , Balasubramanian, G. , Hyngstrom, A. , Sanvanson, P. , & Shaker, R. (2018). Swallow strength training exercise for elderly: A health maintenance need. Neurogastroenterology and Motility, 30(10), e13382. 10.1111/nmo.13382 - DOI - PMC - PubMed
    1. Bharucha, A. E. , Dunivan, G. , Goode, P. S. , Lukacz, E. S. , Markland, A. D. , Matthews, C. A. , Mott, L. , Rogers, R. G. , Zinsmeister, A. R. , Whitehead, W. E. , Rao, S. S. C. , & Hamilton, F. A. (2015). Epidemiology, pathophysiology, and classification of fecal incontinence: State of the science summary for the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) workshop. American Journal of Gastroenterology, 110(1), 127–136. 10.1038/ajg.2014.396 - DOI - PMC - PubMed
    1. Duthie, H. L. , & Watts, J. M. (1965). Contribution of the external anal sphincter to the pressure zone in the anal canal. Gut, 6, 64–68. 10.1136/gut.6.1.64 - DOI - PMC - PubMed
    1. Guaderrama, N. M. , Nager, C. W. , Liu, J. , Pretorius, D. H. , & Mittal, R. K. (2005). The vaginal pressure profile. Neurourology and Urodynamics, 24(3), 243–247. 10.1002/nau.20112 - DOI - PubMed
    1. Jung, S.‐A. , Pretorius, D. H. , Padda, B. S. , Weinstein, M. M. , Nager, C. W. , den Boer, D. J. , & Mittal, R. K. (2007). Vaginal high‐pressure zone assessed by dynamic 3‐dimensional ultrasound images of the pelvic floor. American Journal of Obstetrics and Gynecology, 197(1), 52.e1–52.e7. 10.1016/j.ajog.2007.04.026 - DOI - PMC - PubMed

Publication types

LinkOut - more resources