Constipation is a symptom complex and not merely a disease. In the absence of secondary causes,<sup>34 Rao S.S.C. Constipation Conn's Current Therapy Philadelphia: WB Saunders (1999).  20-30

Cliccare qui per andare alla sezione Riferimenti</sup> it is due to either a neuromuscular dysfunction of the colon—slow transit constipation—or a neuromuscular dysfunction of the defecation unit. In many patients, there is an overlap because colon transit is delayed in two thirds of patients with difficult or disordered defecation.<sup>47 Rao S.S.C., Welcher K., Leistikow J. Obstructive defecation: A failure of rectoanal coordination. Am J Gastroenterol 1998 ;  93 : 1042-1050  [cross-ref]

Cliccare qui per andare alla sezione Riferimenti</sup> In the literature, many terms have been used to describe the constipation that is associated with anorectal dysfunction, including anismus,<sup>8 Duthie G.S., Bartolo D.C.C. Anismus: The cause of constipation? Results of investigation and treatment World J Surg 1992 ;  16 : 831-835  [cross-ref]

Cliccare qui per andare alla sezione Riferimenti, 15 Glia A., Lindberg G., Nilsson L.H. , e al. Constipation assessed on the basis of colorectal physiology Scand J Gastroenterol 1998 ;  33 : 1273-1279

Cliccare qui per andare alla sezione Riferimenti, 32 Preston D.M., Lennard-Jones J. Anismus in chronic constipation Dig Dis Sci 1985 ;  30 : 413-418  [cross-ref]

Cliccare qui per andare alla sezione Riferimenti</sup> pelvic floor dyssynergia,<sup>60 Whitehead W.E., Devrode G., Habib F. , e al. Functional disorders of the anus and rectum The Functional Gastrointestinal Disorders Boston: Little, Brown (1994).  217-263

Cliccare qui per andare alla sezione Riferimenti, 62 Whitehead W.E., Wald A., Diamant N. , e al. Functional disorders of the Anorectum International Working Party Consensus: Rome Criteria II McLean, VA: Degnon Assoc (2000).  483-532

Cliccare qui per andare alla sezione Riferimenti</sup>obstructive defecation,<sup>28 Papachrysostomou M., Smith A. Efects of biofeedback on obstructive defecation: Reconditioning of the defecation reflex? Gut 1994 ;  35 : 242-245

Cliccare qui per andare alla sezione Riferimenti, 47 Rao S.S.C., Welcher K., Leistikow J. Obstructive defecation: A failure of rectoanal coordination. Am J Gastroenterol 1998 ;  93 : 1042-1050  [cross-ref]

Cliccare qui per andare alla sezione Riferimenti</sup>paradoxic puborectalis contraction,<sup>13 Glia A., Gylin M., Gullberg K. , e al. Biofeedback retraining in patients with functional constipation and paradoxical puborectalis contraction: Comparison of anal manometry and sphincter electromyography for feedback Dis Colon Rectum 1997 ;  40 : 889-895  [cross-ref]

Cliccare qui per andare alla sezione Riferimenti, 18 Hull T.L., Fazio V.W., Schroeder T. Paradoxical puborectalis contraction in patients after pelvic pouch construction Dis Colon Rectum 1995 ;  38 : 1144-1146  [cross-ref]

Cliccare qui per andare alla sezione Riferimenti, 19 Jarnerot G. Behavioral medicine treatment in chronic constipation with paradoxical anal sphincter contraction Dis Colon Rectum 1991 ;  35 : 145-150

Cliccare qui per andare alla sezione Riferimenti</sup> pelvic outlet obstruction,<sup>22 Kawimbe B.M., Pappachrysostomou M., Binnie N.R. , e al. Outlet obstruction constipation (anismus) managed by biofeedback Gut 1991 ;  32 : 1175-1179  [cross-ref]

Cliccare qui per andare alla sezione Riferimenti, 26 Martelli H., Devroede G., Arhan P. , e al. Mechanisms of idiopathic constipation: Outlet obstruction Gastroenterology 1978 ;  75 : 623-631

Cliccare qui per andare alla sezione Riferimenti</sup> and spastic pelvic floor syndrome.<sup>3 Bieijenberg G., Kuipers H. Treatment of spastic pelvic floor syndrome with biofeedback Dis Colon Rectum 1987 ;  30 : 101-111

Cliccare qui per andare alla sezione Riferimenti</sup>

Preston and Lennard-Jones<sup>32 Preston D.M., Lennard-Jones J. Anismus in chronic constipation Dig Dis Sci 1985 ;  30 : 413-418  [cross-ref]

Cliccare qui per andare alla sezione Riferimenti</sup> first described the association of paradoxic anal contraction during attempted defecation in patients with constipation and coined the term anismus. These authors believed that this condition was a spastic dysfunction of the anus, analogous to vaginismus. The term anismus implies a psychogenic cause, however, which has not been described in these patients. An international group of experts have proposed the term pelvic floor dyssynergia in preference to anismus because the latter term refers only to a dysfunction of the external anal sphincter, whereas this condition may affect one or more muscles of the pelvic floor.<sup>60 Whitehead W.E., Devrode G., Habib F. , e al. Functional disorders of the anus and rectum The Functional Gastrointestinal Disorders Boston: Little, Brown (1994).  217-263

Cliccare qui per andare alla sezione Riferimenti, 62 Whitehead W.E., Wald A., Diamant N. , e al. Functional disorders of the Anorectum International Working Party Consensus: Rome Criteria II McLean, VA: Degnon Assoc (2000).  483-532

Cliccare qui per andare alla sezione Riferimenti</sup>The pelvic floor is a complex muscular apparatus that serves three important functions: defecation, micturition, and sexual function. All-encompassing terms such as pelvic floor dyssynergia, pelvic outlet obstruction, and spastic pelvic floor syndrome imply that this problem affects most of the pelvic floor and possibly all of its functions. Although some overlap has been described among patients with urinary obstruction and constipation,<sup>54 Thorpe A.C., Williams N.S., Badenoch D.F. , e al. Simultaneous dynamic electromyographic protography and cystometrography Br J Surg 1993 ;  80 : 115-120  [cross-ref]

Cliccare qui per andare alla sezione Riferimenti</sup> most constipated patients do not report sexual or urinary symptoms.<sup>46 Rao S.S.C., Vellema T., Kempf J. , e al. Symptoms, stool patterns and quality of life in patients with dyssynergic defecation Gastroenterology 2000 ;  118 : A782

Cliccare qui per andare alla sezione Riferimenti</sup> These terms are not suitable.

Outlet obstruction <sup>22 Kawimbe B.M., Pappachrysostomou M., Binnie N.R. , e al. Outlet obstruction constipation (anismus) managed by biofeedback Gut 1991 ;  32 : 1175-1179  [cross-ref]

Cliccare qui per andare alla sezione Riferimenti, 26 Martelli H., Devroede G., Arhan P. , e al. Mechanisms of idiopathic constipation: Outlet obstruction Gastroenterology 1978 ;  75 : 623-631

Cliccare qui per andare alla sezione Riferimenti</sup> implies that there is blockage to defecation. It includes functional and structural problems, such as neoplasia, rectal prolapse, anal stenosis, and others. Consequently, outlet obstruction misrepresents a functional disorder. The term obstructive defecation<sup>28 Papachrysostomou M., Smith A. Efects of biofeedback on obstructive defecation: Reconditioning of the defecation reflex? Gut 1994 ;  35 : 242-245

Cliccare qui per andare alla sezione Riferimenti, 47 Rao S.S.C., Welcher K., Leistikow J. Obstructive defecation: A failure of rectoanal coordination. Am J Gastroenterol 1998 ;  93 : 1042-1050  [cross-ref]

Cliccare qui per andare alla sezione Riferimenti</sup> is preferable, but even this falls short of the real pathophysiology because functional conditions, such as mucosal intussusception or rectal prolapse, may obstruct the voluntary act of defecation. The aforementioned terms are less than ideal for describing the real problem in these patients.

Studies have shown that most patients with difficult defecation show a failure of rectoanal coordination that consists of impaired abdominal and rectal pushing forces<sup>36 Rao S.S.C. The technical aspects of biofeedback therapy for defecation disorders Gastroenterologist 1998 ;  6 : 96-103

Cliccare qui per andare alla sezione Riferimenti, 47 Rao S.S.C., Welcher K., Leistikow J. Obstructive defecation: A failure of rectoanal coordination. Am J Gastroenterol 1998 ;  93 : 1042-1050  [cross-ref]

Cliccare qui per andare alla sezione Riferimenti</sup>or paradoxic anal contraction or inadequate anal relaxation.<sup>47 Rao S.S.C., Welcher K., Leistikow J. Obstructive defecation: A failure of rectoanal coordination. Am J Gastroenterol 1998 ;  93 : 1042-1050  [cross-ref]

Cliccare qui per andare alla sezione Riferimenti</sup> A lack of coordination or dyssynergia of the abdominal and pelvic floor muscles that are involved in defecation appears to be the primary underlying mechanism. Consequently the term dyssynergic defecation <sup>32 Preston D.M., Lennard-Jones J. Anismus in chronic constipation Dig Dis Sci 1985 ;  30 : 413-418  [cross-ref]

Cliccare qui per andare alla sezione Riferimenti</sup> more appropriately describes this condition.