Rectal Balloon Expulsion Research Articles

Phenotypic Variation in Functional Disorders of Defecation

Although obstructed defecation is generally attributed to pelvic floor dyssynergia, clinical observations suggest a wider spectrum of anorectal disturbances. Our aim was to characterize phenotypic variability in constipated patients by anorectal assessments. Anal pressures, rectal balloon expulsion, rectal sensation, and pelvic floor structure (by endoanal magnetic resonance imaging) and motion (by dynamic magnetic resonance imaging) were assessed in 52 constipated women and 41 age-matched asymptomatic women. Phenotypes were characterized in patients by principal components analysis of these measurements. Among patients, 16 had a hypertensive anal sphincter, 41 had an abnormal rectal balloon expulsion test, and 20 had abnormal rectal sensation. Forty-nine patients (94%) had abnormal pelvic floor motion during evacuation and/or squeeze. After correcting for age and body mass index, 3 principal components explained 71% of variance between patients. These factors were weighted most strongly by perineal descent during evacuation (factor 1), anorectal location at rest (factor 2), and anal resting pressure (factor 3). Factors 1 and 3 discriminated between controls and patients. Compared with patients with normal (n = 23) or reduced (n = 18) perineal descent, patients with increased (n = 11) descent were more likely (P < or = .01) to be obese, have an anal resting pressure >90 mm Hg, and have a normal rectal balloon expulsion test result. These observations demonstrate that functional defecation disorders comprise a heterogeneous entity that can be subcharacterized by perineal descent during defecation, perineal location at rest, and anal resting pressure. Further studies are needed to ascertain if the phenotypes reflect differences in the natural history of these disorders.

Manometric assessment of idiopathic megarectum in constipated children

Chronic constipation is a frequent finding in children. In this age range, the concomitant occurrence of megarectum is not uncommon. However, the definition of megarectum is variable, and a few data exist for Italy. We studied anorectal manometric variables and sensation in a group of constipated children with megarectum defined by radiologic criteria. Data from this group were compared with those obtained in a similar group of children with recurrent abdominal pain. Anorectal testing was carried out in both groups by standard manometric technique and rectal balloon expulsion test. Megarectum patients displayed discrete abnormalities of anorectal variables and sensation with respect to controls. In particular, the pelvic floor function appeared to be impaired in most patients. Constipated children with megarectum have abnormal anorectal function and sensation. These findings may be helpful for a better understanding of the pathophysiological basis of this condition.

Predictive value of impaired evacuation at proctography in diagnosing anismus.

We aimed to determine the positive predictive value of impaired evacuation during evacuation proctography for the subsequent diagnosis of anismus. Thirty-one adults with signs of impaired evacuation (defined as the inability to evacuate two thirds of a 120 mL contrast enema within 30 sec) during evacuation proctography underwent subsequent anorectal physiologic testing for anismus. A physiologic diagnosis of anismus was based on a typical clinical history of the condition combined with impaired rectal balloon expulsion or abnormal surface electromyogram. Twenty-eight (90%) of the 31 patients with impaired proctographic evacuation were found to have anismus at subsequent physiologic testing. Among the 28 were all 10 patients who evacuated no contrast medium and all 11 patients with inadequate pelvic floor descent, giving evacuation proctography a positive predictive value of 90% for the diagnosis of anismus. A prominent puborectal impression was seen in only three subjects during proctography, one of whom subsequently showed no physiologic sign of anismus. Impaired evacuation during evacuation proctography is highly predictive for diagnosis of anismus.

A Study of the Effect of Distension of the Rectosigmoid Junction on the Rectum and Anal Canal with Evidence of a Rectosigmoid-Rectal Reflex

Purpose.To elucidate the role of the rectosigmoid junction (RSJ) in the mechanism of defecation.Method.Fourteen healthy volunteers were enrolled in the study (10 men, 4 women; mean age 38.2 ± 10.6 years). The pressures in the rectum, anal canal, and RSJ as well as rectal balloon expulsion were recorded in response to balloon distension of the RSJ in increments of 10 ml of carbon dioxide (CO2) to 50 ml. The experiments were repeated after individual anesthetization of the RSJ, rectum, and anal canal. The expulsion of a 50-ml distended balloon located in the anesthetized rectum was tested.Results.RSJ distension with 10 ml of CO2produced no significant pressure changes in the RSJ, rectum, or anal canal. A 20-ml distension effected a significant pressure rise in the RSJ (P< 0.05) and the rectum (P< 0.01) and a decline in the anal canal (P< 0.05); the rectal balloon was expelled to the exterior. Similar pressure changes (P> 0.05) were recorded with a 30-, 40-, and 50-ml balloon distension. The mean latency for the RSJ response was 12.6 ± 2.2 ms and for the rectum 15.8 ± 2.6 ms. The balloon, distended with 50 ml of CO2and located in the rectum, was not expelled to the exterior. Balloon expulsion occurred only with distension with volumes of above 80 ml. Individual anesthetization of the RSJ, rectum, and anal canal followed by RSJ distension produced no significant pressure changes in RSJ, rectum, and anal canal as well as no rectal balloon expulsion.Conclusion.The rectal contraction upon RSJ distension affirms the hypothesis of the possible involvement of a reflex, which we term “rectosigmoid-rectal reflex.” This reflex relationship is evidenced by reproducibility and its absence on anesthetization of either the RSJ or the rectum, both presumably representing the two arms of the reflex arc. It is postulated that stools passing from the sigmoid colon to the rectum distend the RSJ and evoke the rectosigmoid-rectal reflex, which produces rectal contraction. The role of the reflex in defecation disorders needs to be studied.

Descending perineum syndrome: audit of clinical and laboratory features and outcome of pelvic floor retraining.

Our aim was to retrospectively analyze the Mayo Clinic experience of descending perineum syndrome from 1987-1997. Clinical records were abstracted for demographic features, risk factors, results of anorectal and defecation tests, and a mailed questionnaire evaluated outcome and current symptoms. All results are mean +/- SD. Clinically, 39 patients (38 women, one man), mean age 53+/-14 yr, presented with constipation (97%), incomplete rectal evacuation (92%), excessive straining (97%), digital rectal evacuation (38%), and fecal incontinence (15%). Laboratory tests showed anal sphincter resting pressure was 54+/-26 mm Hg, and squeeze pressure was 96+/-35 mm Hg; expulsion from the rectum of a 50-ml balloon required > 200 g added weight in 27%; perineal descent was 4.4+/-1 cm (normal < 4 cm) by scintigraphy. Scintigraphic evacuation, rectoanal angle change during defecation, and perineal descent were abnormal in 23%, 57%, and 78% of the patients, respectively. Associated features included female gender (96%), multiparity with vaginal delivery (55%), hysterectomy or cystocele/rectocele repair (74%). On follow-up, 64% responded; 17 of these 25 responders underwent pelvic floor retraining. At 2-yr median follow-up (range, 1-6 yr), 12 still experienced constipation or excessive straining; their perineal descent was greater than in patients who responded to retraining (p = 0.005). Descending perineum syndrome is identifiable by clinical history and examination, and the most prevalent abnormality on testing is perineal descent > 4 cm; rectal balloon expulsion is an insensitive screening test for descending perineum syndrome. Pelvic floor retraining is a suboptimal treatment for this chronic disorder of rectal evacuation; the extent of perineal descent appears to be a useful predictor of response to retraining.

Descending perineum syndrome: audit of clinical and laboratory features and outcome of pelvic floor retraining

Objective: Our aim was to retrospectively analyze the Mayo Clinic experience of descending perineum syndrome from 1987–1997. Methods: Clinical records were abstracted for demographic features, risk factors, results of anorectal and defecation tests, and a mailed questionnaire evaluated outcome and current symptoms. Results: All results are mean ± SD. Clinically, 39 patients (38 women, one man), mean age 53 ± 14 yr, presented with constipation (97%), incomplete rectal evacuation (92%), excessive straining (97%), digital rectal evacuation (38%), and fecal incontinence (15%). Laboratory tests showed anal sphincter resting pressure was 54 ± 26 mm Hg, and squeeze pressure was 96 ± 35 mm Hg; expulsion from the rectum of a 50-ml balloon required > 200 g added weight in 27%; perineal descent was 4.4 ± 1 cm (normal < 4 cm) by scintigraphy. Scintigraphic evacuation, rectoanal angle change during defecation, and perineal descent were abnormal in 23%, 57%, and 78% of the patients, respectively. Associated features included female gender (96%), multiparity with vaginal delivery (55%), hysterectomy or cystocele/rectocele repair (74%). On follow-up, 64% responded; 17 of these 25 responders underwent pelvic floor retraining. At 2-yr median follow-up (range, 1–6 yr), 12 still experienced constipation or excessive straining; their perineal descent was greater than in patients who responded to retraining ( p = 0.005). Conclusions: Descending perineum syndrome is identifiable by clinical history and examination, and the most prevalent abnormality on testing is perineal descent > 4 cm; rectal balloon expulsion is an insensitive screening test for descending perineum syndrome. Pelvic floor retraining is a suboptimal treatment for this chronic disorder of rectal evacuation; the extent of perineal descent appears to be a useful predictor of response to retraining.

Sacral root stimulation for controlled defecation.

Selective rectal or sphincter neurostimulation aiming at controlled defecation was performed in 10 dogs. While the dogs were under anesthesia, the rectal and rectal neck pressures, balloon expulsion as well as external anal sphincter (EAS) response to stimulation of the second sacral ventral nerve root (S2) and its autonomic and somatic branches were determined. Each of these nerves was stimulated separately using bipolar platinum cuff electrodes. S2 stimulation resulted in rectal and rectal neck pressure elevation as well as increase of EMG activity of EAS without balloon expulsion. Autonomic branch stimulation effected rectal pressure increase and balloon expulsion, while somatic branch stimulation caused increase of rectal neck pressure and EAS EMG activity with no balloon expulsion. S2 stimulation with somatic branch transection produced rectal pressure elevation and balloon expulsion. In contrast to rectal pressure, the rectal neck pressure increased with increasing stimulus frequency. In conclusion, rectal evacuation and sphincteric control could be induced by selective sacral root electrostimulation: S2 stimulation with transection of the somatic branch for the former and pudendal branch stimulation for the latter.

Functional obstructive defaecation

Objective: To study patients with obstructive defaecation to determine quantitatively its pathophysiology and homogeneity. Design: Twenty-two patients with obstructive defaecation were studied by isotope proctography and by conventional methods for quantitative analysis of the pathophysiological factors involved. Methods: Examination of the patients included ano-rectal manometry, the rectal balloon expulsion test, pelvic floor electromyography and isotope proctography. Eleven asymptomatic subjects were studied for comparison. Results: Pelvic floor electromyography revealed increased 'straining electromyographic activity' in all patients (P< 0.001). Patients with obstructive defaecation had impaired rectal sensation and were unable to perform a complete rectal evacuation (54% rectal evacuation) on isotope proctography. The defaecation time was prolonged and was associated with a reduced defaecation rate. Simultaneous recording of intrarectal pressures and external anal sphincter (EAS) electromyography during proctography revealed increased intrarectal pressure (P<0.0001) and EAS electromyographic voltage (P<0.01) during evacuation. The anorectal angles correlated with the pelvic floor movement and the anismus index. The anismus index in these patients correlated with the intrarectal pressure (P<0.02). No increase in the electromyographic voltage of the EAS was observed in any of the control subjects who successfully performed rectal balloon expulsion. Conclusion: Obstructive defaecation is a multifactórial condition involving derangements of rectal sensation and abnormal activity of the pelvic floor and anal sphincter musculature; its homogeneity is affected by the duration of the process.

Basic testing of an artificial pacemaker in the normal and incontinent anorectum.

The role of an artificial pacemaker (AP) in the control of idiopathic fecal incontinence was studied in 15 healthy volunteers (mean age 49.6 years) and 11 patients with idiopathic fecal incontinence (mean age 45.9 years). In the latter, EMG activity of the external anal sphincter (EAS) was diminished, and that of the internal sphincter (IAS) was normal. The pacemaker consisted of a needle, a flat metal piece, a battery and a telegrapher's key. The needle was applied to the IAS and EAS. The rectal and rectal neck pressures were measured by water-perfused tubes, and rectal distension was achieved by a condom-ended catheter. In normal subjects, electric pulsing of either the IAS or EAS caused a significant rectal neck pressure increase (p < 0.01), but insignificant changes in rectal pressure (p > 0.05). Rectal distension with 100 ml of air effected a rectal neck pressure decrease (p < 0.01) and balloon expulsion. IAS pulsing with the rectum distended led to a rectal neck pressure increase (p < 0.001) and rectal pressure decrease (p < 0.0001), but not to balloon expulsion. The rectal neck pressure increased more with EAS pulsing than with IAS pulsing (p < 0.01). In incontinent subjects, IAS pulsing produced a significant rectal neck pressure increase (p < 0.001), while EAS pulsing resulted in an insignificant one (p > 0.05). In the same subjects, IAS pulsing with rectal distension (50 ml air) caused a significant rectal neck pressure increase (p < 0.001) and a significant rectal pressure decrease (p < 0.0001); the rectal balloon was not expelled.(ABSTRACT TRUNCATED AT 250 WORDS)

Electromyography of the pubococcygeus muscles in patients with obstructed defaecation.

The function of the pubococcygeus muscles during defaecation straining was compared in 10 women with obstructed defaecation and 12 age-matched control subjects. Video-proctography in each patient showed failure to evacuate the rectum and sagging of the pelvic floor during attempted defaecation. Trans-perineal concentric needle electromyography in the puborectalis muscle and transvaginal electromyography in the pubococcygeus muscle was carried out during defaecation straining and during attempted rectal balloon expulsion. Contraction of the pubococcygeus muscle was observed in 10 of the 12 control subjects and in 2 of the 10 patients with obstructed defaecation (P < 0.005). Virtually equal proportions of subjects in each group showed relaxation or contraction of the puborectalis muscle during straining. There was significant perineal descent on straining in the patient group (P = 0.005). This group of patients with obstructed defaecation showed failure of the pubococcygeus muscles to contract, perhaps due to neuropathic weakness of the muscles. The puborectalis muscle did not cause obstructed defaecation in these patients, and the concept of "paradoxical" contraction of this muscle is questioned.