Assessment of Fecal Incontinence

Why should we be interested?

• Common problem• Can be iatrogenic• Results of surgery frequently imperfect• Can have an adverse effect on quality of

life• Significant cost for the Society

Common medical problem that is under-reported to physicians

Second leading cause of nursing home placement

3% of women who give birth by vaginal delivery will develop Some degree of FI

Introduction

Incidence and prevalence

Perry et al, 2002. Prevalence of faecal incontinence in adults aged 40 years or more living in the community

Background: definition• Faecal incontinence is defined as

involuntary loss of faeces• Commonly classified according to:

– character of leakage– symptom– presumed primary underlying cause

Diagnosis

• HISTORY

• EXAMINATION

• INVESTIGATION

History

• LISTEN to what is being said

• LISTEN to the problem

• LISTEN to the effect on their life

• Define incontinence: flatus vs. stool (liquid vs. solid) • Characterize frequency, duration, severity• Soiling?...fistula, prolapse, hemorrhoids • Urgency? ..... decreased rectal compliance • Medications: laxatives, antibiotics, pancreatic enzyme • Past surgical history: ano-rectal, obstetric

Initial evaluation History

Examination of the anus• Skin tags, fissures, fistulas• Descent• Gape• Strain• Length and angle• Muscle bulk• Voluntary contraction

The specific questions

• Defaecation• Consistency• Urgency• Frequency• Leakage

Pathophysiology and Etiology

Partial incontinence – loss of control to flatus and minor soiling

Major incontinence – frequent and regular deficiency in the ability to control stool of normal consistency

Normal Continence

External sphincter: - Somatic innervation - 15% continence

Internal sphincter: - Visceral innervation - 85% continence

Secondary Musclesof continencePrimary Muscles

of continence

External Anal Sphincter

Fecal Incontinencephysiologic factors

stool consistency rectal and anal sensation

rectal compliancepelvic floor function

can lead to a defective continence mechanism

Fecal Incontinence Altered stool consistency

Inflammatory bowel diseaseInfectious diarrheaLaxative abuseRadiation enteritisShort bowel syndromeMalabsorption syndrome

Fecal IncontinenceInadequate rectal compliance

Inflammatory bowel diseaseAbsent rectal reservoir (ileoanal, low ant. resection)Rectal neoplasmsRadiation TherapyCollagen vascular disease (scleroderma, amyloidosis, dermatomyositis)

Fecal Incontinence Inadequate rectal sensation

Dementia, CVA, MS, brain or spinal cord injury/neoplasm, sensory neuropathy

Diabetes – multifactorial, impaired rectal sensation is important

Overflow incontinenceFecal impaction – leading cause of incontinence in institutionalized elderly patients

Fecal IncontinenceDescending perineal syndrome

Constant straining during defecation

Traction neuropathy of the nerves

Denervation of puborectalis and EAS

The reflex responsiveness of the anal region

Fecal incontinence associated with spinal cord injury

Fecal IncontinenceSphincter defect (Internal and/or External)

Traumatic

Obstetric injury prolonged difficult labor (forceps

application) episiotomy complications

Anorectal surgery anal fistula surgery (most common)

hemorrhoidectomy

Incidence of Perineal Trauma

• 90% of incontinent women with an obstetric history have a sphincter defect (Burnett, S.J. BJS 1991)

• Women with 30/40 tear

– 74% Symptomatic– 59% Incontinent of Gas– 90% Sphincter Defect (Goffeng, A.R. Act.OGS 1998)

• 35% of Primiparous women will have a sphincter defect after delivery (13% symptomatic) (Sultan, A.H. NEJM 1993)

Childbirth & Fecal Incontinence

• 549 prospective fecal urgencyvag 7.3% vsCS 3.1% Chaliha 99 Obstet Gyn

259 consecutive women delivered single unit31 elective CS no FIPrimaparous delivered vaginally 13% FI

Abromowitz Dis Colon Rectum 2000

Incontinence after birth

MacLennan and collegues, BJOG 2000

No births

Caesareansection

Vaginal delivery

Instrumental delivery

Stress 11% 33% 41% 44%

Urge 4% 10% 19% 20%

Faecal 2% 4% 5% 11%

How often do these problems occur?

The Mechanism Of Obstetric Injury

Obstetric InjuryMechanisms

Rectovaginal septum - rectocoele

Ischaemic injury - fistula

Sphincter complex - incontinence

Investigations

FunctionAno-rectal

ManometryAno-rectal

Electrophysiology

StructureEndoanal Ultrasound Magnetic Resonance

ImagingDefecography

MorphologyEndoscopy

Anorectal manometry

Anorectal manometry

Measurement of both resting and voluntary sphincter squeeze pressure

Incontinent patients – low resting and voluntary squeeze pressure

Estimate threshold for rectal sensation/compliance, recto-anal inhibitory reflex

Anorectal manometry in fecal incontinence

Anal Endosonography

An ultrasound probe is placed in the anal canal or transvaginally to detect sphincter injuries and to evaluate pelvic floor structures

Normal anatomy as viewed by anal endosonography

Normal anatomy as viewed by anal endosonography

Faecal IncontinenceStructural Defect

Electrophysiologic testsEMG – needle electrodes into the superficial portion of the external sphincter or puborectalis muscle – myoelectric activit

Pudendal nerve terminal motor latency – measures the delay between the application of an electrical stimulus and external sphincter muscle response. Prolonged – pudendal neuropathy

SPHINCTEROPLASTYPNTML & Neuropathy

Is PNTML reliable in predicting poor outcome ?

• difficult to quantify neuropathy• cut-off value• value of unilateral prolonged latency

Defecography

Evacuation is monitored with flouroscopy

Assessment of the anorectal angle at rest and during defecation

Excessive perineal descent, failure of the puborectalis muscle to relax, rectocele and internal intususception

Summary• Listen to the story• Ask the questions• Examine the bottom• Do the tests• Fit the jigsaw together• Consider the alternatives for treatment