258 Gut 1997; 41: 258–262 Paradoxical sphincter contraction is rarely indicative of anismus Gut: first published as 10.1136/gut.41.2.258 on 1 August 1997. Downloaded from W A Voderholzer, D A Neuhaus, A G Klauser, K Tzavella, S A Müller-Lissner, N E Schindlbeck Abstract inability to defaecate a water-filled rectal Background—Anismus is thought to be a balloon. Its main feature is an inappropriate cause of chronic constipation by produc- contraction (paradoxical sphincter contraction, ing outlet obstruction. The underlying PSC) rather than relaxation of the anal sphinc- mechanism is paradoxical contraction of ter or puborectalis muscle during straining. the anal sphincter or puborectalis muscle. Paradoxical sphincter relaxation may be However, paradoxical sphincter contrac- shown by digital rectal examination, manom- tion (PSC) also occurs in healthy controls, etry, electromyographic examination, and—as so anismus may be diagnosed too often a failure of the anorectal angle to widen—on because it may be based on a non-specific defaecography. As PSC is also found in control finding related to untoward conditions subjects without anorectal disease3 it may be a during the anorectal examination. non-specific finding related to untoward condi- Aims—To investigate the pathophysiologi- tions during examination. It seems natural that cal importance of PSC found at anorectal an embarrassed patient does not show normal manometry in constipated patients and in defaecation behaviour. Being afraid of losing patients with stool incontinence. stools may play an important part in PSC dur- Methods—Digital rectal examination and ing straining. anorectal manometry were performed in The aim of this study was therefore to find 102 chronically constipated patients, 102 out the pathophysiological importance of the patients with stool incontinence, and in 18 anorectal manometric finding “paradoxical controls without anorectal disease. In 120 sphincter contraction during straining”. of the 222 subjects defaecography was also performed. Paradoxical sphincter con- Methods traction was defined as a sustained in- One hundred and two consecutive constipated http://gut.bmj.com/ crease in sphincter pressure during patients and 102 consecutive patients with straining. Anismus was assumed when stool incontinence were included from our gas- PSC was present on anorectal manometry troenterological outpatient department. Pa- and digital rectal examination and the tients were considered to be constipated if they anorectal angle did not widen on defae- had had fewer than three bowel movements per cography. week and/or a frequent (>25%) need to strain Results—Manometric PSC occurred during defaecation for more than one year and on September 28, 2021 by guest. Protected copyright. about twice as often in constipated pa- who presented to the hospital because of tients as in incontinent patients (41.2% constipation. Organic disease of the colon had versus 25.5%, p<0.017) and its prevalence been excluded by colonoscopy, laboratory was similar in incontinent patients and findings (TSH), and further investigations by Medizinische Klinik, controls (25.5% versus 22.2%). Oroanal or the general practitioner. Stool incontinence Klinikum Innenstadt, rectosigmoid transit times in constipated was defined as an unintentional loss of faeces at University of Munich, patients with and without PSC did not dif- least once a week for more than six months. Munich, Germany fer significantly (total 64.6 (8.9) hours ver- W A Voderholzer Eighteen patients referred for colonic sur- D A Neuhaus sus 54.2 (8.1) hours; rectosigmoid 14.9 gery or for colonoscopy to exclude colonic A G Klauser (2.4) hours versus 13.8 (2.5) hours). malignancy, who were completely free of K Tzavella Conclusions—Paradoxical sphincter con- symptoms, acted as controls. N E Schindlbeck traction is a common finding in healthy controls as well as in patients with chronic Department of constipation and stool incontinence. ANORECTAL MANOMETRY Internal Medicine, Anorectal manometry was performed using a Hence, PSC is primarily a laboratory Park-Klinik seven-lumen side hole catheter (Arndorfer, artefact and true anismus is rare. Weissensee, Berlin, Greendale, Wisconsin, USA) which was con- Germany (Gut 1997; 41: 258–262) A Müller-Lissner tinuously perfused with distilled water at a rate Keywords: anismus; paradoxical sphincter contraction; of 0.1 ml/min per recording site (fluid per- Correspondence to: constipation; stool incontinence; anorectal manometry fusion device, Mui, Mississauga, Canada). Dr W A Voderholzer, There were six side holes, 0.5 cm apart at Medizinische Klinik, Klinikum Innenstadt, about 15 cm from the tip of the catheter, radi- Universität München, Anismus is thought to cause constipation by ally orientated for examination of the anorectal Ziemssenstrasse 1, D-80336 producing outlet obstruction during defaeca- sphincter muscle, and another side hole was München, Germany. tion. It has been described especially in young situated 5 cm from the tip of the catheter for Accepted for publication or middle aged women with chronic determination of the rectal pressure. At the 10 March 1997 constipation12and may be associated with the very tip of the catheter a latex balloon was Paradoxical sphincter contraction and anismus 259 TABLE 1 Mean (SEM) demographic and manometric data of pathophysiological groups 100 p = 0.017 studied. Results of transit time measurements are mentioned in the text and figure 1 80 Chronic Gut: first published as 10.1136/gut.41.2.258 on 1 August 1997. Downloaded from Controls constipation Stool incontinence 60 Sex ratio (female/male) 10/8 94/8* 89/13* 40 Age (years) 49.1 (3.3) 52.9 (1.6) 61.2 (1.3)*† Symptom duration (years) — 20.5 (1.6) 5.2 (1.1)† 20 Sphincter pressures: Frequency (%) Resting (mm Hg) 62.1 (4.5) 50.8 (1.8)* 32.9 (1.8)*† 0 Maximal (mm Hg) 102.6 (6.5) 89.7 (2.8)* 62.9 (3.8)*† Controls Constipation Incontinence RAIR thresholds: First appearance (ml) 20.0 (0.8) 21.2 (1.1) 22.1 (1.0) PSC No PSC Maximal relaxation (ml) 85.3 (5.4) 85.0 (3.5) 78.2 (4.1) Rectal sensitivity thresholds: Figure 1: Frequency of manometric paradoxical sphincter Perception (ml) 22.2 (1.5) 28.9 (2.0) 28.2 (1.6) contraction (PSC) in the three groups studied. The ordinate Urge (ml) 44.7 (3.4) 74.7 (4.1)* 61.3 (3.4) shows the percentage of patients in each group with and PSC (n (%)) 4 (22.2) 42 (41.2) 26 (25.5)‡ without PSC. If the data from the controls and incontinent patients were pooled the p value decreased (p=0.01). PSC, paradoxical sphincter contraction; RAIR, rectoanal inhibitory reflex. *p<0.05 versus controls, †p<0.05 versus constipation, ‡p=0.017 versus constipation. asked to empty his or her bowel as completely as possible. Paradoxical sphincter contraction TABLE 2 Mean (SD) demographic and manometric data of patients with and without manometric paradoxical sphincter contraction (PSC). The results did not change when was defined as a failure to widen the anorectal groups were stratified according to constipation, stool incontinence and controls angle and anal canal during straining accompa- nied by a persistent dorsal indentation at the PSC (n=72) No PSC (n=150) upper border of the anal canal and remnants of Sex ratio (female/male) 58/14 135/15 rectal contrast medium after defaecation indi- Age (years) 55.7 (2.0) 56.7 (1.2) cating grossly delayed rectal emptying. Symptom duration 12.7 (1.6) 14.5 (1.7) Sphincter pressures: Transit time was measured in 62 (60.8%) Resting pressure (mm Hg) 45.8 (2.8) 42.4 (1.6) constipated patients using the radio-opaque Maximal squeeze pressure (mm Hg) 81.7 (4.3) 76.1 (3.0) RAIR thresholds: marker method. Briefly, 20 radio-opaque First appearance (ml) 21.5 (1.4) 21.5 (0.8) encapsulated pellets were ingested for 14 days Maximal relaxation (ml) 83.8 (4.9) 81.5 (2.9) at 0900 hours and one day after the last capsule Rectal sensitivity thresholds: Perception (ml) 29.2 (2.3) 27.4 (1.4) was taken an abdominal x-ray was performed Urge (ml) 69.4 (5.0) 64.4 (2.9) at 0900 hours. The number of pellets on the abdominal film was counted and multiplied by RAIR, rectoanal inhibitory reflex. 1.2 to give the oroanal transit time.5 For deter- attached which could be blown up by a syringe mination of segmental colonic transit time lines to a volume of 150 ml. were drawn on the abdominal film as described 6 Examination started with a rectal digital previously and defined as right colon, left examination with the patient lying on the left colon, and rectosigmoid colon. http://gut.bmj.com/ side. During digital examination the sphincter pressure and reaction of the sphincter muscle STATISTICS and pelvic floor during straining and squeezing The Mann-Whitney U test was used to were determined. The manometry tube was compare numerical data of the diVerent groups then introduced into the rectum up to about and the ÷2 test was used to compare nominal 20 cm from the dentate line and slowly data. A p value of <0.05 was considered withdrawn until a rise in pressure indicated the significant. on September 28, 2021 by guest. Protected copyright. position of the anorectal sphincter muscle. The length of the anal high pressure zone was then Results determined by slowly pulling back the manom- DEMOGRAPHIC DATA etry tube stepwise by 1 cm. The patient was One hundred and two constipated patients, asked to squeeze and strain three times. The 102 incontinent patients, and 18 healthy balloon on the tip of the catheter was blown up controls were studied. The incontinent patients stepwise (10 ml per step) and the balloon vol- were older than the constipated patients and ume at which the patient experienced sensation control subjects, while symptom duration was and urge to defaecate was determined by longer in the constipated patients than in the asking the patient what he or she felt.