Rectal prolapse and faecal incontinence

01OverviewDefinition, clinical context and the essential points that orientate the chapter.

Rectal prolapse can be external full-thickness descent, mucosal prolapse or internal intussusception. It is associated with pelvic-floor weakness, chronic straining, obstetric injury, neurological disease and connective-tissue or anatomical factors; full-thickness disease often coexists with incontinence because the prolapse chronically stretches the sphincters.

Continence depends on stool consistency, rectal capacity and sensation, internal and external sphincters, pelvic-floor coordination, cognition, mobility and timely toilet access. Assessment must therefore look beyond a single sphincter test and understand when, what and why leakage occurs.

The central decision is whether a reversible bowel or environmental factor can restore control, whether structural prolapse needs colorectal repair, and which specialist intervention fits physiology, frailty and patient goals.

Key points

Full-thickness rectal prolapse produces concentric circumferential folds; prolapsing haemorrhoids form discrete radial columns, while mucosal prolapse is a more limited lining descent.
Symptoms include a protruding mass, mucus, bleeding, incomplete evacuation, obstructed defaecation, urgency and passive leakage; patients may need to photograph an intermittent prolapse.
Faecal incontinence means involuntary loss of stool that is a social or hygienic problem and should be asked about directly and without stigma.
Urgency incontinence suggests inability to defer despite sensation; passive leakage suggests impaired sensation or resting sphincter function; post-defaecation seepage suggests incomplete evacuation.
First identify treatable drivers such as diarrhoea, faecal impaction with overflow, medicines, infection, rectal loading, cognitive or mobility barriers and inadequate toilet access.
A focused examination includes abdomen, perineum, prolapse during strain, anal sensation, digital rectal examination, sphincter squeeze and relevant neurological findings.
Initial continence care aims for predictable formed stool, planned toileting, skin protection and pelvic-floor or bowel-retraining support rather than reflex antidiarrhoeal prescribing.
Persistent symptoms may need anorectal physiology, endoanal ultrasound, defaecography and multidisciplinary treatments such as biofeedback, irrigation, sphincter repair, rectopexy or sacral neuromodulation.

02AetiologyUnderlying causes, associations and risk factors, with why each one matters.

Pelvic support failure

Age, obstetric injury, connective-tissue weakness and prior pelvic surgery can weaken rectal fixation and anal sphincter support.

Chronic straining or diarrhoea

Constipation, obstructed defaecation and repeated loose stool expose pelvic structures to traction and worsen urgency or passive leakage.

Neurological and sphincter dysfunction

Spinal, peripheral nerve and central neurological disease impair rectal sensation, motor control and coordinated evacuation, causing incontinence without obvious prolapse.

03PathophysiologyThe causal sequence from the underlying abnormality to symptoms and harm.

1
Rectal intussusception and descent
The upper rectum folds into itself and may progress through the anal canal as full-thickness concentric prolapse.
2
Sphincter stretch and neuropathy
Repeated prolapse stretches anal muscles and pudendal nerves, reducing resting pressure, squeeze and rectal sensation during defaecation.
3
Failure of stool control
Loose stool, reduced sensation, weak sphincters and incomplete evacuation combine to produce urgency, passive leakage or post-defaecation seepage.

04Clinical features and red flagsSymptoms, examination findings, patterns of presentation and time-critical warnings.

External full-thickness prolapse

A circumferential red mass emerges on straining with concentric rings, often accompanied by mucus, bleeding, incomplete evacuation or leakage. It may reduce spontaneously or need manual assistance.

Incarcerated prolapseRed flag

A swollen irreducible segment with escalating pain, bleeding, ulceration or dusky colour suggests venous obstruction and threatened ischaemia, requiring urgent specialist reduction or surgery.

Urge incontinence

The patient recognises the need to defaecate but cannot postpone it long enough to reach a toilet. Loose stool, reduced squeeze strength, small rectal capacity or proctitis may contribute.

Passive incontinence

Stool or mucus escapes without awareness, suggesting impaired rectal sensation, low resting tone, internal sphincter dysfunction or neurological disease; ask about nocturnal and continuous leakage.

Overflow leakage

Constipation, abdominal discomfort and rectal loading with loose seepage around impacted stool are common in frail or neurologically impaired people and can be worsened by antidiarrhoeal treatment.

Neurological emergencyRed flag

Abrupt incontinence with urinary retention, saddle numbness, bilateral sciatica or leg weakness may represent cauda equina syndrome and requires immediate spinal pathway assessment rather than routine pelvic-floor referral.

Cancer or inflammatory warningRed flag

Weight loss, anaemia, persistent bleeding, a hard rectal mass, nocturnal diarrhoea or new bowel change requires colorectal investigation even when prolapse or incontinence is visible.

05InvestigationsWhat to request, why it matters and how to interpret it.

Investigation order

Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.

01
Bowel and continence diaryFirst step
Why
Define stool form, timing, triggers, urgency, leakage and toileting context.
Interpretation and limitations
Record several representative days including diet, medicines and pad use. Patterns can expose diarrhoea, post-defaecation seepage or access barriers and provide a baseline for treatment.
02
Perineal inspection with strain
Why
Distinguish rectal prolapse, mucosal descent, haemorrhoids and skin injury.
Interpretation and limitations
Concentric folds favour full-thickness prolapse; radial columns favour haemorrhoids. If intermittent, a patient-supplied photograph or commode examination may prevent a missed diagnosis.
03
Digital rectal and focused neurological examination
Why
Assess loading, mass, resting tone, squeeze, sensation and neurological cause.
Interpretation and limitations
Rectal impaction can produce overflow; reduced resting or squeeze tone suggests sphincter dysfunction but bedside assessment is approximate. Saddle sensory or lower-limb abnormalities demand urgent spinal evaluation.
04
Lower gastrointestinal endoscopy
Why
Exclude cancer, proctitis or another mucosal cause when indicated.
Interpretation and limitations
Select flexible sigmoidoscopy or colonoscopy according to bleeding, anaemia, altered habit and cancer risk. Structural prolapse does not make red flags benign.
05
Anorectal manometry
Why
Measure resting and squeeze pressures, sensation and rectoanal coordination.
Interpretation and limitations
Results help phenotype incontinence and plan biofeedback or surgery but correlate imperfectly with lived function. Interpret alongside stool consistency, examination and endoanal imaging.
06
Endoanal ultrasound
Why
Identify internal or external sphincter defects.
Interpretation and limitations
An obstetric or operative defect may support repair in a selected patient, but anatomy alone does not guarantee that sphincteroplasty will restore continence.
07
Defaecography or dynamic pelvic MRI
Why
Demonstrate internal prolapse, rectocele and evacuation mechanics.
Interpretation and limitations
Use when symptoms and clinic findings disagree or before complex pelvic-floor surgery. Interpret in a multidisciplinary context because asymptomatic descent is common.

06Differential diagnosisRealistic alternatives and the features that help distinguish them.

Prolapsing haemorrhoids or mucosa

Discrete radial columns suggest haemorrhoids, while limited mucosal descent lacks the circumferential full-thickness folds of rectal prolapse.

Pelvic-organ prolapse

A vaginal wall or uterine bulge has a different origin on pelvic examination but may coexist through shared support failure.

Prolapsing tumour or polyp

An irregular focal mass, bleeding or ulceration requires endoscopic and histological assessment rather than assuming benign prolapse.

07ManagementImmediate care, first-line treatment, alternatives and escalation.

01BaselineStructured continence assessmentFirst stepAny involuntary stool loss that causes a social or hygienic problem.

1Ask sensitively about solid, liquid and flatus leakage, awareness, urgency, frequency, obstetric and surgical history, stool form, diet, medicines, cognition, mobility and toilet access.
2Treat immediate reversible causes including faecal loading, acute diarrhoea, infection and medication effects; investigate red flags and provide skin protection and practical containment meanwhile.
3Aim for a predictable Bristol type 3 to 4 stool using individualised diet, fibre or antidiarrhoeal strategies, avoiding a generic high-fibre instruction that could worsen loose stool or bloating.
4Refer persistent symptoms to a specialist continence service for bowel retraining, pelvic-floor exercises, biofeedback and targeted physiology or imaging.

02ProlapseReducible full-thickness rectal prolapseConcentric rectal protrusion without ischaemia or obstruction.

1Confirm the type and assess constipation, incontinence, frailty, previous pelvic surgery and associated vaginal or urinary prolapse; address stool consistency and straining while awaiting review.
2Teach gentle manual reduction only when appropriate, using lubrication and a relaxed position, and provide urgent safety-netting for an irreducible, painful or discoloured prolapse.
3Refer to a pelvic-floor colorectal service; select abdominal rectopexy or a perineal Delorme or Altemeier approach according to anatomy, function, operative fitness, recurrence risk and informed preference.
4After repair, monitor recurrence, constipation, evacuation, continence, anastomotic complications and mesh-related issues when applicable under the operative service.

03EscalationPersistent faecal incontinenceEscalationClinically important leakage despite optimised stool and supervised conservative treatment.

1Review the diagnosis and goals with a multidisciplinary continence team, using manometry, endoanal ultrasound or defaecography only when results will guide a specific intervention.
2Offer structured pelvic-floor training, bowel retraining, biofeedback, irrigation or containment devices according to cognition, dexterity, physiology and patient preference.
3Consider a trial of sacral nerve stimulation when conservative treatment has failed and sphincter repair is inappropriate, proceeding to implantation only after meaningful trial benefit.
4Reserve sphincter repair, neosphincter procedures or stoma formation for carefully selected cases after explaining durability, complications and the valid goal of reliable symptom control rather than anatomical normality.

04EmergencyIncarcerated prolapse responseIrreducible oedematous prolapse with pain, bleeding, obstruction or threatened tissue.

1Assess haemodynamics and tissue viability, provide analgesia, keep nil by mouth and obtain immediate senior colorectal and anaesthetic review.
2A trained specialist may attempt gentle reduction with oedema-reducing measures when tissue appears viable; repeated force must stop if reduction fails or ischaemia is suspected.
3Proceed to emergency operative management for necrosis, perforation, obstruction, uncontrolled bleeding or unsuccessful safe reduction, selecting the operation to physiology and anatomy.
4After recovery, reassess continence, bowel habit, nutrition and pelvic-floor function and arrange appropriate rehabilitation and recurrence surveillance.

Key medicines and prescribing safety3 treatments · regimens, roles and cautions

Firms loose stool and reduces frequency or urgency in selected incontinence phenotypes.

Loperamide

Start low and titrate timing and amount under the continence plan.

First exclude impaction, acute inflammatory diarrhoea and obstruction. Excess dosing causes constipation and overflow; use cautiously with severe colitis and follow BNF or local advice.

Can improve stool consistency when both loose fragmented stool and incomplete evacuation contribute.

Bulk-forming fibre preparation

Introduce gradually with adequate fluid and adjust against the stool diary.

May worsen bloating or leakage in some patients and is unsuitable in obstruction or impaction. Individualise rather than prescribing fibre automatically for every phenotype.

Protects perianal skin from moisture, enzymes and repeated wiping while control improves.

Barrier skin preparation

Apply a thin layer after gentle cleansing as directed by continence nursing.

Avoid thick layers that obscure inspection or prevent pad absorption, and investigate candidiasis, ulceration, pressure injury or allergy when skin does not improve.

08ComplicationsImportant consequences, why they occur and why they matter clinically.

Incarceration and ischaemia

An irreducible oedematous prolapse can strangulate, ulcerate and become necrotic, requiring urgent colorectal assessment and possible surgery.

Ulceration, bleeding and mucus

Repeated mechanical trauma causes mucosal ulcer, discharge and anaemia or soiling that can mimic inflammatory and neoplastic disease.

Dermatitis and social restriction

Persistent leakage damages perianal skin and drives embarrassment, isolation, falls during urgency and loss of independent daily activity.

09Monitoring and follow-upTreatment response, safety checks and longer-term review.

Use the same bowel diary and patient-reported severity measure to track episodes, urgency, stool form, pad use and participation over time.
Check for constipation and rectal loading after antidiarrhoeal changes; reduced visible leakage can conceal developing overflow or obstructed defaecation.
Review hydration, nutrition, skin integrity, falls risk, cognition, dexterity and ability to reach a toilet, especially in frail or care-home residents.
After prolapse surgery, monitor recurrence, new constipation, worsened or improved continence, urinary dysfunction and procedure-specific wound or mesh complications.
During sacral neuromodulation, record trial response, device-site problems, programming needs and MRI or procedure compatibility through the implanting service.

10Special situationsVariants, exceptions and circumstances that change the usual approach.

Folds reveal the structure

Concentric rings suggest the full rectal wall has prolapsed; discrete radial columns are more typical of haemorrhoids. Photographs can capture an intermittent event accurately.

Stool consistency is treatment

A marginal sphincter may contain formed stool but not liquid stool. Correcting diarrhoea can transform function even when anatomy is unchanged.

Impaction can look like diarrhoea

Liquid stool seeping around a hard rectal mass is overflow. Adding loperamide before examining for loading can aggravate the underlying problem.

Continence is more than pressure

Sensation, capacity, cognition, mobility and toilet access can dominate symptoms, so a low manometric value is not a complete diagnosis or operation mandate.

Trial before permanent stimulation

Sacral neuromodulation begins with a temporary evaluation. Meaningful symptom improvement during that phase supports, but does not guarantee, benefit from implantation.

Surgical route reflects the person

Abdominal and perineal prolapse repairs differ in invasiveness, recurrence and functional effects. Frailty and priorities can be as important as anatomical elegance.

11Common pitfallsFrequent interpretation and management errors.

01
Calling circumferential rectal prolapse large haemorrhoids without examining the fold pattern.
02
Prescribing loperamide before excluding faecal impaction with overflow.
03
Ignoring a new neurological deficit in a patient reporting sudden incontinence.
04
Giving generic high-fibre advice despite diarrhoea or severe bloating.
05
Ordering anorectal physiology without a question that will change management.
06
Choosing prolapse surgery without discussing constipation, recurrence and continence outcomes.