D. Z. Lubowski

Is paradoxical contraction of puborectalis muscle of functional importance

Paradoxical contraction of the puborectalis muscle during simulated defecation straining (anismus) has been cited as a cause of constipation. The functional specificity of this phenomenon was evaluated in 79 patients, 50 with constipation, 21 with idiopathic perineal pain, and eight with solitary rectal ulcer syndrome. Electromyogram evidence of paradoxical puborectalis contraction was observed in 38 (76 percent), ten (48 percent), and four (50 percent) of these patients, respectively. All patients with solitary rectal ulcer syndrome had difficulty defecating; defecation was normal in all patients with perineal pain. These observations suggest that paradoxical contraction of the puborectalis muscle is not a specific finding, and that it is not the sole cause of constipation in patients with anismus.

Sacral nerve stimulation induces pan-colonic propagating pressure waves and increases defecation frequency in patients with slow-transit constipation.

Objective  Colonic propagating sequences are important for normal colonic transit and defecation. The frequency of these motor patterns is reduced in slow‐transit constipation. Sacral nerve stimulation (SNS) is a useful treatment for faedcal and urinary incontinence. A high proportion of these patients have also reported altered bowel function. The effects of SNS on colonic propagating sequences in constipation are unknown. Our aims were to evaluate the effect of SNS on colonic pressure patterns and evaluate its therapeutic potential in severe constipation.

Spatial and temporal organization of pressure patterns throughout the unprepared colon during spontaneous defecation

OBJECTIVE:The aim of this study was to examine colonic motor events associated with spontaneous defecation in the entire unprepared human colon under physiological conditions.METHODS:In 13 healthy volunteers a perfused, balloon-tipped, 17-lumen catheter (outer diameter, 3.5 mm; intersidehole spacing, 7.5 cm) was passed pernasally and positioned in the distal unprepared colon.RESULTS:In the hour before spontaneous defecation, there was an increase in propagating sequence frequency (p = 0.04) and nonpropagating activity when compared to basal conditions (p < 0.0001). During this hour the spatial and temporal relationships among propagating sequences demonstrated a biphasic pattern. Both the early (proximal) and late (distal) colonic phases involved the whole colon and were characterized by respective antegrade and retrograde migration of site-of-origin of arrays of propagating sequences. There was a negative correlation between propagating sequence amplitude and the time interval from propagating sequence to stool expulsion (p = 0.008).CONCLUSIONS:The colonic motor correlate of defecation is the colonic propagating sequence, the frequency and amplitude of which begin to increase as early as 1 h before stool expulsion. During the preexpulsive phase, the spatial and temporal relationship among the sites of origin of individual propagating sequences demonstrate a stereotypic anal followed by orad migration, which raises the possibility of control by long colocolonic pathways.

Glyceryl trinitrate ointment for the treatment of chronic anal fissure

PURPOSE: A randomized, double-blind, placebo-controlled trial was performed to test the effect of intra-anal glyceryl trinitrate ointment in patients with chronic anal fissures that would normally have been treated by sphincterotomy. Long-term follow-up was then performed to assess fissure healing. METHODS: Patients with chronic anal fissures were randomly assigned to 0.2 percent topical glyceryl trinitrate ointment or placebo. Anal manometry was performed before treatment, one week later, and 48 hours after treatment ceased at four weeks. Fissure healing was assessed by an observer blinded to the treatment arm. Pain was recorded on a linear analog scale. At the completion of the trial, treatment was continued with glyceryl trinitrate until fissure healing was obtained or lateral sphincterotomy was performed if required for ongoing pain. A long-term follow-up assessment was made at a mean of 29 (range, 25–33) months. RESULTS: There was a significant reduction in anal resting pressure at Week 1 with glyceryl trinitrate (P=0.001) but not placebo, and at Week 4 there was a significant reduction in pain score with glyceryl trinitrate (P=0.001) and placebo (P=0.01) and a significant reduction in fissure grade with glyceryl trinitrate (P=0.0001) and placebo (P=0.02). Forty-six percent of fissures healed with glyceryl trinitrate and 16 percent healed with placebo (P=0.001). At long-term follow-up in 40 of 43 patients, 14 patients (35 percent) had undergone lateral sphincterotomy, and in the remainder who were treated with glyceryl trinitrate there was a significant reduction in pain score (P=0.0002). Seventeen patients attended for repeat manometry and fissures were healed with glyceryl trinitrate in ten (59 percent) cases. High internal sphincter pressures persisted at long-term follow-up in patients successfully treated with glyceryl trinitrate, indicating that the sphincter is the cause rather than effect of anal fissure. CONCLUSION: Topical glyceryl trinitrate produces a successful internal sphincterotomy, which resulted in long-term healing of 59 percent of chronic anal fissures and significant improvement in pain. Internal sphincter spasm is the cause of chronic anal fissure.

Results of colectomy for severe slow transit constipation

PURPOSE: This study assesses the outcome of a standardized operation performed by two surgeons for severe idiopathic slow transit constipation that was resistant to laxative treatment. METHODS: Fifty-nine consecutive patients, 4 men and 55 women, with a mean age of 42.3 years, underwent colectomy with ileorectal anastomosis. Slow colonic transit was demonstrated in each case. Fifty-two patients were available for follow-up, with median time to follow-up being 42 (range, 3–81) months. RESULTS: Median bowel frequency was 4 per 24 hours. Sixty-nine percent had four or less bowel movements daily. Ten percent used antidiarrheal medication regularly. One patient had a stoma for recurrent severe constipation. Mean continence score was 1.8 (on a scale of 0–20); six patients were incontinent, and four of these six had normal preoperative anal manometry. Fourteen patients (27 percent) had difficulty with rectal evacuation. Preoperative defecating proctography was a poor predictor of postoperative evacuation difficulties. Twenty-seven patients (52 percent) had persisting abdominal pain, but there was a significant improvement in the degree of pain (P<0.00001). Forty-seven patients (90 percent) were satisfied with the outcome of the operation (and would elect to have it done again). Dissatisfied patients had recurrent constipation or diarrhea and incontinence. CONCLUSION: Colectomy with ileorectal anastomosis produces a satisfactory functional outcome in the majority of patients undergoing surgery for severe constipation with proven slow colonic transit.

Transanal endoscopic microsurgery excision: is anorectal function compromised?

AbstractPURPOSE: Transanal endoscopic microsurgery is a new technique that has not yet found its place in routine practice. The procedure results in dilation of the anal sphincter with a large-diameter operating sigmoidoscope, sometimes for a prolonged period. The purpose of the present study was to assess the effect of transanal endoscopic microsurgery on anorectal function. METHODS: Eighteen consecutive patients undergoing transanal endoscopic microsurgery excision of rectal tumors, of whom 13 were available for evaluation, were included. Continence was scored by a numeric scale before surgery and at three and six weeks after surgery. Anorectal physiology studies were performed preoperatively and six weeks postoperatively with manometry, pudendal nerve motor terminal latency, anal mucosal electrosensitivity, rectal balloon volume studies, and endoanal ultrasound. RESULTS: There was a significant reduction in mean anal resting pressure (104 ± 32 cm H2O before surgery, 73 ± 30 cm H2O after surgery; P = 0.0009). There was no significant change in squeeze or cough pressure, pudendal nerve terminal motor latency, anal mucosal electrosensitivity, or rectal balloon study volumes. Fall in resting pressure was significantly correlated with length of operating time (r2 =0.39, P = 0.047). There was no significant change in mean continence score after surgery. CONCLUSION: Transanal endoscopic microsurgery results in a reduction in internal sphincter tone. This did not affect continence in a short-term study.

Relation between perineal descent and pudendal nerve damage in idiopathic faecal incontinence

In 60 patients with idiopathic anorectal incontinence, without neurological disease, there was a significant relationship, shown by regression analysis, between the pudendal nerve terminal motor latency and the extent of perineal descent during straining (r0.59;p<0.001), and the plane of the perineum on straining (r−0.61;p<0.001). These data are consistent with the suggestion that perineal descent can lead to stretch-induced damage to the perineal nerves in this condition.

Prolonged multi-point recording of colonic manometry in the unprepared human colon: providing insight into potentially relevant pressure wave parameters

OBJECTIVES: To determine the feasibility of and derive normative data for prolonged, 24-h, multipoint, closely spaced, water perfused manometry of the unprepared human colon. METHODS: In 14 healthy volunteers, 24-h recordings were made using a water perfused, balloon-tipped, 17 lumen catheter which was passed pernasally and positioned so that 16 recording sites spanned the colon at 7.5 cm intervals from cecum to rectum. The area under the pressure curve and propagating pressure wave parameters were quantified for the 16 regions. High amplitude propagating sequences were defined as were rectal motor complexes. RESULTS: Nasocolonic recording was well tolerated and achievable. Propagation sequences, including high amplitude propagating sequences, originated in the cecum (0.32 ± 0.05/h) more frequently than in other regions and the extent of propagation correlated significantly with proximity of the site of sequence origin to the cecum (p < 0.001). Propagation velocity of propagating sequences was greater than high amplitude propagating sequences (p = 0.0002) and region-dependent, unlike high amplitude propagating sequences (p < 0.01). The frequency of propagating sequences did not increase after the meal, but frequency of high amplitude propagating sequences was increased significantly by the meal (p < 0.01). Rectal motor complexes were seen throughout the colon with no apparent periodicity. CONCLUSIONS: Prolonged, multipoint, perfusion manometry of the unprepared colon provides improved spatial resolution of colonic motor patterns and confirms the diurnal and regional variations in propagating pressure waves detected in the prepared colon. The study demonstrates differences between high amplitude propagating sequences and propagating sequence parameters that may have functional significance; and also, that the rectal motor complex is a ubiquitous pan colonic motor pattern.

Oral sodium phosphate solution is a superior colonoscopy preparation to polyethylene glycol with bisacodyl

PURPOSE: The aim of this study was to compare the efficacy and patient tolerance of two bowel preparations for colonoscopy. METHODS: Three hundred twenty-three consecutive patients undergoing colonoscopy were randomly assigned to receive either oral sodium phosphate, or 2 liters of polyethylene glycol solution preceded by the stimulant laxative bisacodyl. Patients were asked to record the effects of the preparation, noting any vomiting, nausea, or abdominal pain, and to determine a discomfort rating on a scale of 1 to 5. One hundred sixty-nine patients were assigned to the oral sodium phosphate solution, and 154 to polyethylene glycol with bisacodyl. Surgeons were blinded to the preparation used and rated the quality of the bowel preparation on a scale of 1 to 5. RESULTS: Ninety-nine percent of patients in the sodium phosphate group drank all of the solution as opposed to 91 percent of patients in the polyethylene glycol with bisacodyl group. Patients in the sodium phosphate group reported significantly less discomfort (P=0.002). No significant difference was reported for vomiting, nausea, or abdominal pain associated with the preparations. The quality of bowel cleansing was considered by the colonoscopists significantly better for the sodium phosphate group than the polyethylene glycol with bisacodyl group (P<0.000001). CONCLUSIONS: Colonoscopy preparation with sodium phosphate solution is better tolerated and more effective than polyethylene glycol with bisacodyl.

Design of a high-sensor count fibre optic manometry catheter for in-vivo colonic diagnostics

The design of a fibre Bragg grating based manometry catheter for in-vivo diagnostics in the human colon is presented. The design is based on a device initially developed for use in the oesophagus, but in this instance, longer sensing lengths and increased flexibility were required to facilitate colonoscopic placement of the device and to allow access to the convoluted regions of this complex organ. The catheter design adopted allows the number of sensing regions to be increased to cover extended lengths of the colon whilst maintaining high flexibility and the close axial spacing necessary to accurately record pertinent features of peristalsis. Catheters with 72 sensing regions with an axial spacing of 1 cm have been assembled and used in-vivo to record peristaltic contractions in the human colon over a 24hr period. The close axial spacing of the pressure sensors has, for the first time, identified the complex nature of propagating sequences in both antegrade (towards the anus) and retrograde (away from the anus) directions in the colon. The potential to miss propagating sequences at wider sensor spacings is discussed and the resultant need for close axial spacing of sensors is proposed.