Normal Defecation and Mechanisms for Continence

  • Mônica Milinkovic de la Quintana
  • Tania das Graças de Souza Lima
  • Vera Lúcia Conceição de Gouveia Santos
  • Maria Helena Baena de Moraes Lopes


The mechanism of fecal continence is a complex process, composed of a series of events, which are influenced by the consistency, volume, and speed with which the fecal material reaches the rectum; the sensitivity and distensibility of the rectum vault; and factors related to the sphincter muscles, which involve sensorial and mechanical components that require muscular and nervous integrity. The defecatory mechanism is complex and involves a sequence of events, which integrates smooth and striated muscle and the central, somatic, autonomic, and enteric nervous systems. Normal defecation involves the rapid, semi-voluntary emptying of the rectum and a variable part of the colon, and it requires a high degree of coordination to achieve the evacuation of solid or semisolid feces. In this chapter, anatomical and physiological components of the anorectal portion of the gastrointestinal tract will be explained, according to their relevance to maintain continence.


Fecal incontinence Defecation Constipation Diarrhea 



To Dr. José Marcio Neves Jorge, Dr. Ilario Froehner Junior, and Dr. Afonso Henrique da Silva e Sousa Júnior for making available the figures used in this chapter, to Mr. Marcos Retzer (in memorium), the artist who created them and to Ms. Nádia Bollos Mosca Luque for formatting or modifying the figures and adding the English legends.


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Copyright information

© Springer International Publishing AG, part of Springer Nature 2018

Authors and Affiliations

  • Mônica Milinkovic de la Quintana
    • 1
  • Tania das Graças de Souza Lima
    • 2
  • Vera Lúcia Conceição de Gouveia Santos
    • 3
  • Maria Helena Baena de Moraes Lopes
    • 4
  1. 1.Nipo Brasileiro HospitalSão PauloBrazil
  2. 2.University of Rio de JaneiroRio de JaneiroBrazil
  3. 3.School of NursingUniversity of São PauloSão PauloBrazil
  4. 4.Faculty of NursingUniversity of CampinasCampinasBrazil

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