S T U S T Influence of Body Position on Defecation in Humans Department of Internal Medicine, Division of Neurology, Sakura Medical Center, Toho University, Sakura, Japan, Department of Urology, Tokyo Women’s Medical University, Tokyo, Japan, Aishin Seiki Inc., Tokyo, Japan, Clinical Physiology Unit, Sakura Medical Center, Toho University, Sakura, Japan, Department of Radiology, Sakura Medical Center, Toho University, Sakura, Japan, Department of Neurology, Chiba University, Chiba, Japan, and Department of Urology, Dokkyo Medical College, Tochigi, Japan Chairman:Dr.Hung-Chi Yang Presenter:Bee-Yen Lim Adviser:Dr. Yi-Chun Du 1

Outline ٥ Introduction ٥ Purposes ٥ Material and Methods ٥ Results ٥ Discussion and Conclusions ٥ References 2

Introduction ٥ Normal defecation is thought to necessitate three components: spontaneous phasic rectal contraction that starts during storage (autonomic component) relaxation of the anal canal with an enlarged anorectal angle straining (somatic component) 3

Purposes ٥ To compare three positions for defecation by measuring abdominal pressure and the anorectal angle simultaneously. 4 ٥ To compare the straining forces applied when sitting or squatting during defecation.

Material and Methods ٥ Six healthy volunteers(one male, five females) ٥ Age range:36–44 years(mean age:41 years old) ٥ Apparently normal bowel function ٥ A triple-lumen 9F catheter was inserted into the anus ٥ An 8F catheter (used to measure abdominal [bladder] pressure) was inserted into the bladder 5

Results 6

Conclusions ٥ The results of the present study, taken together with earlier findings, suggest that the greater the hip flexion achieved by squatting the straighter the rectoanal canal will be, and accordingly, less strain will be required for defecation. 7

References ٥ Ryuji Sakakibara,Kuniko Tsunoyama, Hiroyasu Hosoi, Osamu Takahashi,Megumi Sugiyama,Masahiko Kishi, Emina Ogawa, Hitoshi Terada,Tomoyuki Uchiyama, Tomonori Yamanishi,“Influence of Body Position on Defecation in Humans,” LUTS, 2, 16–21, 2010 ٥ Dov Sikirov, “Comparison of Straining During Defecation in Three Positions,” Digestive Diseases and Sciences, 48(7), , 2003 ٥ ٥ ٥ ٥ ٥ ٥ 8