Anorectal sensory and motor function in neurogenic fecal incontinence. Comparison between multiple sclerosis and diabetes mellitus.

We measured anorectal sensory and motor function in 11 patients with multiple sclerosis and fecal incontinence, 11 continent patients with multiple sclerosis, 10 diabetics with fecal incontinence, and 12 healthy control subjects. The threshold volume at which patients with multiple sclerosis and fecal incontinence experienced rectal sensation was higher than that in healthy controls (42.7 +/- 6.2 mL vs. 13.3 +/- 2.8 mL; P less than 0.01) and was similar to that in incontinent diabetics (36.5 +/- 5.7 mL). Patients with multiple sclerosis and incontinent diabetics also showed increased thresholds of phasic external sphincter contraction compared with controls (P less than 0.05). Diabetics with incontinence had reduced resting and maximal voluntary anal sphincter pressures compared with controls (P less than 0.05), whereas patients with multiple sclerosis and incontinence showed only decreased maximal voluntary anal sphincter pressures (P less than 0.01 vs. controls and diabetics). Incontinent patients with multiple sclerosis also required smaller volumes of rectal distention to inhibit internal sphincter tone compared with diabetics and controls (P less than 0.01). Decreased maximal voluntary squeeze pressures were less severe in continent patients with multiple sclerosis than in incontinent patients with multiple sclerosis. We conclude that impaired function of the external anal sphincter and decreased volumes of rectal distention to inhibit the internal anal sphincter or both may contribute to fecal incontinence in multiple sclerosis. In addition, increased thresholds of conscious rectal sensation in some incontinent patients with multiple sclerosis and diabetes mellitus may contribute to fecal incontinence by impairing the recognition of impending defecation.

Contributions of evacuation proctography and anorectal manometry to evaluation of adults with constipation and defecatory difficulty.

We prospectively evaluated 36 patients who complained of chronic constipation and/or defecatory difficulties to determine the role of anorectal manometry and evacuation proctography in delineating the pathogenesis of these complaints. Twenty patients with constipation also underwent a colonic transit study with radioopaque markers, which identified one group with normal transit (N = 10) and another with slow transit (N = 10). Nine of 36 patients (25%) had inappropriate puborectalis muscle contraction or exhibited weak expulsion efforts during evacuation proctography, and these correlated highly with poor rectal emptying of barium paste (20 +/- 6% vs 61 +/- 5% in patients with normal relaxation; P less than 0.01). However, poor rectal emptying did not correlate with the presence of high-grade intussusceptions, large rectoceles, anorectal angles at rest or with straining, rectal diameter, clinical features, or colonic transit. Moreover, abnormal expulsion patterns as seen with anorectal manometry correlated poorly with the presence of inappropriate puborectalis contraction and decreased rectal emptying by proctography. Although anatomic abnormalities occurred frequently in patients with constipation and/or defecatory difficulties, they were also prevalent in asymptomatic controls. In view of these findings, surgical intervention to correct anatomic abnormalities in patients with constipation and/or defecatory difficulties should be considered only with great caution.

Psychological and physiological characteristics of patients with severe idiopathic constipation.

This study prospectively evaluated psychological profiles and selected parameters of colonic and anorectal sensorimotor function in 25 consecutive patients who were referred for severe idiopathic constipation. Measurement of colonic transit of radiopaque markers divided patients into those with normal transit (n = 10) and those with slow transit (n = 15). As measured by the Hopkins Symptom Checklist, patients with normal transit constipation demonstrated significantly higher scores for psychological distress in the global symptoms index and nine clinical subscales than did those with slow transit constipation and gastrointestinal control subjects (n = 25). Both groups with constipation had decreased rectal sensation compared with controls but there was no relationship to rectal compliance or threshold of internal sphincter relaxation. There was also no relation between abnormalities of anorectal parameters, including expulsion dynamics, and psychological profiles in two groups. Measurement of colonic transit and psychological profiles in patients with severe idiopathic constipation identify two groups of patients with respect to possible pathogenesis of symptoms. Accordingly, different therapeutic approaches may be required, one behaviourally and psychologically based and the other focused on the possible modification of disordered colonic transit.