01OverviewDefinition, clinical context and the essential points that orientate the chapter.
External rectal prolapse is circumferential descent of the full rectal wall beyond the anal verge. The protruding bowel is often initially reducible and appears only during defaecation, but later may descend on walking or standing. Internal intussusception remains within the rectum or anal canal and requires a different correlation between imaging and symptoms. Mucosal prolapse involves the lining rather than the whole bowel wall. These distinctions matter because a haemorrhoid procedure will not correct a full-thickness support defect, and an incidental internal finding is not itself an indication for major pelvic surgery.
The anatomical problem reflects failure of the rectal and pelvic-floor support system, often with a deep pelvic pouch, a mobile rectum, redundant sigmoid and levator separation. Repeated descent stretches the anal sphincter and may promote inhibitory reflexes, contributing to leakage. Constipation can coexist through impaired evacuation, straining or more general bowel dysfunction. Neither symptom proves a single mechanism. Surgery therefore has linked but separate goals: return the bowel to its proper position, improve daily function and avoid new constipation, urgency, pain or incontinence. Discuss realistic tradeoffs before selecting the technique.
Key points
- External full-thickness rectal prolapse typically has concentric mucosal rings; haemorrhoidal or mucosal prolapse usually has radial folds or discrete columns.
- Assess colour, tenderness and reducibility immediately: compromised or irreducible bowel needs urgent colorectal care and timely surgery if reduction fails or viability is threatened.
- Choose elective repair from prolapse length, constipation, continence, pelvic anatomy and fitness for anaesthesia; chronological age alone does not choose the operation.
- Stool regulation and pelvic-floor rehabilitation improve symptoms but cannot anatomically cure established external full-thickness prolapse.
- Delorme removes a mucosal sleeve and plicates muscle in short prolapse; Altemeier removes full-thickness prolapsed bowel and creates a coloanal anastomosis.
- Abdominal rectopexy fixes the rectum; posterior dissection may worsen constipation, while ventral mesh repair brings specific implant-consent and governance requirements.
- Review anatomical recurrence and bowel function separately: correcting the visible prolapse does not guarantee restoration of continence.
02AetiologyUnderlying causes, associations and risk factors, with why each one matters.
Support failure
Weakening or disruption of rectal fixation and pelvic-floor support permits circumferential descent, often alongside levator separation, a deep pelvic pouch and excessive bowel mobility.
Functional loading
Chronic straining and pelvic-floor dysfunction may coexist with prolapse. Previous obstetric or pelvic injury can contribute to impaired support, but affected adults have diverse histories.
03PathophysiologyThe causal sequence from the underlying abnormality to symptoms and harm.
- 1Full-wall descent
The rectal wall telescopes downwards and emerges through the anal canal, producing circumferential folds that differ from the radial configuration of isolated mucosal or haemorrhoidal prolapse.
- 2Continence disruption
Repeated descent stretches the sphincter complex and interferes with anal closure. Associated neural dysfunction and inhibitory reflexes can contribute to leakage even when stool is normally formed.
- 3Venous congestion
Entrapment at the anal canal impedes venous drainage, causing oedema that further hinders reduction. Continued compromise can progress from congestion to ischaemic injury and necrosis.
04Clinical features and red flagsSymptoms, examination findings, patterns of presentation and time-critical warnings.
With consent, privacy and a chaperone, inspect during straining when necessary. A commode examination or a patient-provided photograph can reveal intermittent disease absent on the couch. Concentric rings favour full-thickness prolapse; radially arranged columns favour prolapsing haemorrhoids. Record length, circumferential extent, reducibility, mucosal injury and viability rather than relying on the patient’s use of the word piles.
Ask about stool consistency, time spent straining, incomplete evacuation, digital assistance, urgency and leakage of gas, liquid or solid stool. Establish pad use and effects on work, intimacy and leaving home. A bowel diary and a consistent continence or constipation score provide a meaningful baseline. Severe constipation deserves an explanation before an operation that might add further outlet or transit difficulty.
Digital examination assesses resting tone, squeeze, masses and coordination when tolerable. Ask about obstetric injury, prior pelvic operations, urinary leakage and a vaginal bulge; assess other compartments or involve urogynecology. Pelvic-floor dysfunction can span several organs, and correcting only the most visible defect may leave the dominant symptom untreated.
A longstanding painless reducible prolapse becomes an emergency when it is trapped, increasingly painful or discoloured. Assess vital signs, abdomen and hydration alongside the bowel. Mucosal oedema alone does not prove full-thickness necrosis, but uncertainty about viability requires senior assessment. Serial forceful manipulation can damage tissue and postpone definitive treatment.
Assess cardiopulmonary reserve, frailty, cognition, mobility, previous abdominal surgery and the practical support needed after an operation. Some older adults tolerate laparoscopic repair well, while a younger person may require a perineal approach because of substantial comorbidity. Discuss willingness to accept an abdominal procedure, an anastomosis, a mesh implant or a possible recurrence in exchange for a particular recovery profile.
05InvestigationsWhat to request, why it matters and how to interpret it.
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
Selective lower gastrointestinal endoscopyFirst step - Why
- Exclude a lead-point lesion or another explanation for bleeding before elective repair.
- Interpretation and limitations
- Colonoscopy is particularly relevant when cancer symptoms, screening requirements or operative planning warrant it. Prolapse-related trauma can bleed, but this explanation should not hide a neoplasm, inflammatory disease or solitary rectal ulcer. Urgent compromised prolapse should not wait for elective bowel preparation.
- 02
Defaecography or dynamic pelvic MRI - Why
- Clarify internal descent, evacuation and associated pelvic-compartment defects when these affect the plan.
- Interpretation and limitations
- Dynamic imaging can distinguish internal intussusception, rectocele and enterocele. Supine MRI may underrepresent descent compared with seated evacuation. The 2025 ventral-rectopexy consensus favours imaging in preoperative assessment, particularly for complex or recurrent disease; imaging is less useful when an urgent irreducible external prolapse is already clinically evident.
- 03
Anorectal physiology in selected functional uncertainty - Why
- Characterise sphincter function and defaecatory coordination to guide rehabilitation and expectations.
- Interpretation and limitations
- Manometry, sensory assessment and balloon expulsion can identify functional deficits and provide a baseline. These tests support interpretation of constipation or incontinence; they do not replace observing the anatomical prolapse or guarantee that surgery will restore normal function.
- 04
Preoperative or emergency blood tests - Why
- Assess anaemia, organ function and physiological consequences appropriate to presentation.
- Interpretation and limitations
- FBC may reveal blood loss; renal function and electrolytes inform perioperative optimisation. In an unwell patient, blood gas, lactate and other sepsis investigations support resuscitation, but a reassuring isolated result cannot establish bowel viability or justify delaying surgical review.
06Differential diagnosisRealistic alternatives and the features that help distinguish them.
Prolapsing haemorrhoids
Enlarged anal cushions descend as discrete columns with radial folds. They may bleed or require manual reduction without involving the full circumference and thickness of the rectal wall.
Internal intussusception
The bowel infolds within the rectum or anal canal without external emergence. It may be associated with impaired evacuation, but its functional significance varies between patients.
Prolapsing lead-point lesion
A rectal polyp or other mass can descend through the anus and cause bleeding. A focal lesion differs from the uniform circumferential appearance of uncomplicated full-thickness prolapse.
07ManagementImmediate care, first-line treatment, alternatives and escalation.
01Worked caseShort prolapse with limited cardiopulmonary reserveFirst stepA 79-year-old woman has recurrent reducible external prolapse and leakage despite stool regulation.+
- 1Examination during straining demonstrates a viable 3 cm circumferential prolapse with concentric folds. Her baseline is liquid leakage twice weekly without troublesome constipation; appropriate colonic assessment finds no lead-point lesion. Cardiopulmonary assessment identifies substantial risk from prolonged general anaesthesia and pneumoperitoneum, so the team discusses a perineal repair.
- 2After explaining recurrence, bleeding, urgency and the possibility of persistent incontinence, she chooses a Delorme procedure. The surgeon removes the mucosal sleeve and plicates the underlying muscle; this short prolapse is suitable for that approach. The choice follows her anatomy, function and operative risk, rather than an age cutoff.
- 3At six weeks the wound has healed and straining examination shows no external recurrence. Her diary records one episode of liquid leakage during the preceding month, an improvement but not complete functional recovery. She continues bowel-consistency measures and begins targeted pelvic-floor rehabilitation.
- 4At the three-month assessment the prolapse remains reduced during the activity that previously provoked it, and leakage remains infrequent. The team records both anatomical and functional findings and gives a route back for renewed protrusion, difficulty evacuating, bleeding or acute irreducibility; these observed results do not promise lifelong freedom from recurrence.
02Urgent pathwayTrapped or threatened rectal prolapseA prolapse cannot be reduced or develops pain, discolouration or systemic illness.+
- 1Call the surgical team promptly, assess circulation and abdomen, provide analgesia and resuscitation as needed, and keep the patient fasting if surgery is likely. Inspect the mucosa without repeated traumatic manipulation; suspected ischaemia, necrosis or perforation requires immediate operative decision-making.
- 2When the bowel appears viable and there is no concern for perforation, a clinician may attempt gentle reduction with appropriate analgesia. A topical osmotic agent such as sugar can reduce oedema and assist reduction, as described by ACPGBI; this manoeuvre is a bridge to timely care and must not delay surgery when reduction fails.
- 3DefinitiveEscalationEscalate failed reduction or doubtful viability to emergency repair or resection. An abdominal or perineal approach depends on the patient’s physiology, bowel condition and operative findings; no single emergency operation is correct for every patient. After successful reduction, arrange expedited definitive assessment because recurrence and another incarceration remain possible.
03Elective planningMatch the repair to the functional problemDefinitiveA fit adult seeks definitive treatment for symptomatic external full-thickness prolapse.+
- 1Compare abdominal and perineal approaches with the patient after assessing constipation, continence and pelvic compartments. Abdominal fixation is an established option in patients able to tolerate it; minimally invasive surgery can improve recovery when expertise and anatomy permit. Preserve the distinction between a reasonable option and a proven universally superior procedure.
- 2Explain suture rectopexy and the effect of posterior mobilisation on bowel function. Adding sigmoid resection can be considered when prolapse coexists with preoperative constipation, but introduces an anastomosis and may be less attractive when significant baseline incontinence dominates. Avoid choosing resection solely because the sigmoid looks redundant.
- 3AlternativeFor ventral rectopexy, discuss limited anterior dissection, the selected permanent or biological implant, alternative non-mesh repairs and possible persistent or new functional symptoms. Mesh-specific problems include erosion, infection, fistulation and rare sacral discitis. The 2025 consensus states that ventral rectopexy may not be appropriate with active pelvic malignancy, pregnancy, fistulising rectovaginal disease or pelvic sepsis. Relative constraints include proctitis or inflammatory bowel disease, significant pelvic endometriosis and chronic pelvic pain; assess these individually with the MDT and patient rather than treating them as blanket exclusions. The UK Pelvic Floor Society position calls for trained surgeons, MDT selection and recorded outcomes; describe that dated position accurately alongside contemporary consent practice.
- 4Compare perineal alternatives: Delorme is suited to a short segment, whereas Altemeier is a full-thickness perineal rectosigmoidectomy with a coloanal anastomosis. Discuss anastomotic leak where bowel is resected, possible urgency and recurrence, and the individual tradeoff between operative burden and durability. Agree the intended functional endpoint and follow-up before surgery.
08ComplicationsImportant consequences, why they occur and why they matter clinically.
Entrapment and ischaemia
A previously reducible prolapse may become trapped and swollen. Progressive vascular compromise can cause mucosal ulceration, necrosis or perforation with systemic physiological deterioration.
Persistent bowel dysfunction
Constipation, urgency and incontinence can substantially limit daily activity and social confidence. Anatomical descent and pre-existing muscular or neural abnormalities can contribute in different proportions.
Traumatic mucosal injury
Repeated exposure and friction can produce discharge, superficial ulceration and bleeding. These changes can coexist with other colorectal disease and do not exclude a separate lesion.
09Monitoring and follow-upTreatment response, safety checks and longer-term review.
- After repair, assess pain, temperature, bleeding, voiding and return of bowel function; worsening abdominal or pelvic pain with fever requires assessment for a surgical complication.
- Check the anastomotic or perineal wound where relevant and investigate discharge, sepsis or persistent bleeding rather than treating these as inevitable recovery.
- Repeat the baseline bowel diary and functional score, asking separately about straining, incomplete evacuation, urgency and liquid or solid leakage.
- Assess recurrence during provoking activity or straining when symptoms return; persistent constipation without external recurrence needs functional reassessment rather than automatic reoperation.
- For a mesh repair, new persistent pelvic or back pain, vaginal or rectal bleeding, discharge or fistula symptoms warrant specialist assessment for an implant complication even after initial recovery.
10Special situationsVariants, exceptions and circumstances that change the usual approach.
Internal findings need clinical correlation
Internal intussusception can accompany obstructed defaecation, but a radiological finding does not establish causation. Bowel optimisation and pelvic-floor treatment precede selected surgery for symptomatic internal disease; NICE guidance on internal prolapse should not be presented as an external-prolapse recommendation.
Continence may improve incompletely
Reduction removes chronic sphincter stretch and prolapse-related interference with closure, so continence may improve after repair. Established muscular or neural damage can persist. Documenting residual leakage is more useful than declaring success solely because no bowel protrudes.
Mesh consent remains specific
Ventral abdominal mesh and transvaginal implants are different procedures, but that distinction does not remove implant risks. Discuss the chosen material, alternatives, uncertainty and the surgeon’s relevant outcome data without importing a universal complication percentage from an old series.
Constipation is not one diagnosis
An outlet problem, slow transit and a disorder of gut–brain interaction can overlap. A technically sound suspension may not resolve each mechanism; selecting an operation without identifying the dominant functional problem can leave substantial symptoms despite anatomical correction.
11Common pitfallsFrequent interpretation and management errors.
- 01
Treating concentric full-thickness prolapse as haemorrhoids because the patient describes a lump at the anus.
- 02
Using chronological age as the only reason to exclude an abdominal operation or mandate a perineal repair.
- 03
Repeating forceful reduction attempts on dark, painful bowel instead of escalating threatened viability.
- 04
Claiming that a mesh operation or any single alternative has proven superiority for every anatomical and functional presentation.
- 05
Reporting anatomical success without asking whether constipation, urgency, pain or incontinence has improved.