Educational draft · awaiting clinical reviewThe full textbook explains uncertainty but does not replace live national or local guidance, specialist advice, or current prescribing information.
Faecal incontinence and constipation
Medicine of older adults · UK scope · Sources checked 27 Aug 2026 · Clinical review pending
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Obstruction, megacolon or acute neurological bowel
Severe distension, persistent vomiting, peritonism, systemic toxicity, absent stool and flatus, rapidly progressive weakness, saddle anaesthesia or major rectal bleeding can indicate obstruction, perforation, toxic megacolon or cauda equina disease.
Action: Use ABCDE and glucose, keep oral laxatives withheld when obstruction is possible, obtain urgent abdominal and rectal assessment with laboratory tests and imaging, and activate surgical, gastroenterology, sepsis or spinal pathways according to findings.
Overview
Distinguish true faecal incontinence from overflow and functional toileting failure, identify obstruction, neurological and cancer danger, and restore predictable bowel emptying with cause-specific, dignified and practical care.
Describe the bowel pattern precisely: frequency, Bristol form, straining, incomplete emptying, urgency, passive leakage, awareness, nocturnal events, pad use and time spent toileting. Ask when the last satisfactory complete bowel movement occurred rather than the last smear or loose stool. Record baseline and recent change, diet, fluids, mobility, toilet access, cognition, mood, previous surgery, childbirth and neurological disease.
Reconcile medicines and recent changes. Opioids, anticholinergics, iron, calcium, aluminium antacids and verapamil commonly slow transit; diuretics contribute through dehydration; metformin, antibiotics and laxative excess loosen stool. Do not stop beneficial cardiovascular or symptom treatment casually. Opioid initiation should usually include anticipatory bowel management rather than waiting for impaction.
Practice
Two practice questions
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Question 1 of 2
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Medicine of older adultsOriginal SBA
Loose leakage with loading
An 86-year-old taking opioids has frequent small amounts of watery stool, abdominal fullness and a rectum packed with hard stool. What is the best initial management?
Sources and review status5 sources · checked 27 Aug 2026 · clinical review pending+
Sources
Sources and review status
National guidance is shown before implementation-dependent detail. Typical adult dose examples remain subject to patient factors, contraindications and the live BNF or specialist protocol. Source check completed 27 Aug 2026; clinical approval remains outstanding.
Examine hydration, abdomen, hernias and neurological function. Inspect perianal skin, prolapse, haemorrhoids, fissure and soiling with consent and a chaperone as appropriate. Digital rectal examination assesses rectal stool, mass, tenderness, anal tone, voluntary squeeze and possible dyssynergia; an empty rectum does not exclude proximal loading or slow transit.
Treat red flags first. Obstruction symptoms require urgent imaging and surgical assessment before oral loading regimens. New saddle or bilateral leg signs require emergency spinal care. Persistent change, rectal bleeding, anaemia, weight loss or mass follows colorectal investigation. Acute bloody diarrhoea, fever or toxicity requires infection, inflammatory and ischaemic assessment rather than antimotility treatment.
For uncomplicated constipation, address cause and routine. Make fluids accessible within heart or kidney limits, establish foot-supported upright toileting with privacy, and exploit the gastrocolic response after meals. Increase fibre gradually when intake and hydration are adequate; severe loading, slow transit, megacolon or dysphagia can make indiscriminate bulk fibre uncomfortable or hazardous.
Select laxative from stool and mechanism. Macrogol draws water into stool and is useful for maintenance and oral disimpaction after obstruction is excluded. Add or use a stimulant when motility is inadequate; consider a softener or rectal agent for hard distal stool. Frailty, swallowing, fluid restriction, electrolyte risk and carer capacity determine formulation and pace. Reassess rather than stacking indefinite agents blindly.
Impaction treatment is a defined clearance episode. Confirm or strongly support loading, assess obstruction and hydration, then use an oral macrogol disimpaction regimen when suitable. Suppository or enema choice depends on whether stool is hard or soft and where it lies; manual removal is exceptional, skilled and analgesia-conscious. After clearance, establish maintenance immediately because rectal sensation and mobility remain impaired.
For faecal incontinence, first produce a predictable softly formed stool and complete evacuation. Treat diarrhoeal disease, reduce inappropriate laxatives, schedule toileting after meals and improve access and clothing. NICE recommends loperamide as initial antidiarrhoeal when loose stool contributes and no contraindication exists; start very low and titrate to stool consistency because excessive dosing recreates constipation and overflow.
Continence services can provide pelvic-floor and anal-sphincter training, sensory retraining, biofeedback, bowel irrigation and device advice after baseline management. Specialist tests such as anorectal manometry, endoanal ultrasound, defaecography or transit studies are selected when the result will guide advanced conservative or surgical care, not routinely before basic assessment.
Functional care can be decisive. Use prompted toileting linked to the person's bowel pattern, safe transfer equipment, foot support, simple clothing and rapid carer response. Protect skin with gentle cleansing, drying and barrier products, avoiding harsh rubbing. Pads contain but do not treat leakage. Discuss dignity and the person's priorities explicitly.
Review stool form, complete emptying, episodes, pain, skin, hydration, appetite, mobility and carer burden. A written bowel plan should state regular and as-needed medicines, maximum use, what constitutes no response, when rectal assessment occurs and red flags for urgent help. Communicate it across hospital, care home, community pharmacy, GP and carers.
Key points
Constipation includes hard or infrequent stool, straining, incomplete emptying or obstructed defaecation; daily stool does not exclude retention.
Faecal incontinence is involuntary loss of solid or liquid stool; classify urge, passive, seepage, overflow and functional patterns.
First-line assessment uses a bowel and food-fluid history, Bristol stool form, medicine review, abdominal and perianal examination and digital rectal examination when appropriate.
Always exclude faecal loading before prescribing loperamide for apparent diarrhoea or incontinence in a frail older adult.
Review opioids, anticholinergics, iron, calcium, verapamil, diuretics, laxatives, metformin and antibiotics, balancing changes against the original indication.
First-line constipation care combines accessible fluids, regular unhurried toileting after meals, movement, adequate fibre when safe and a titrated laxative regimen.
Treat impaction before maintenance; oral macrogol is commonly used when obstruction is excluded, with rectal treatment selected from stool location and tolerance.
For faecal incontinence, optimise stool consistency and bowel emptying before pelvic-floor training, biofeedback, irrigation or surgical referral.
NICE recommends loperamide as the preferred initial antidiarrhoeal for faecal incontinence with loose stool when contraindications and loading are excluded, starting low and titrating.
A community bowel plan must specify target stool, medicine dose, toileting timing, assistance, skin care, escalation and who reviews it.
Aetiology
01
Faecal loading and overflow
Slow transit, dehydration, immobility, opioids and ignored urge produce rectal impaction with liquid stool leaking around the mass.
02
Sphincter and pelvic-floor dysfunction
Obstetric or surgical injury, neuropathy, prolapse and age-related muscle weakness reduce continence and coordinated evacuation during ordinary bowel movements.
03
Loose or urgent stool
Infection, inflammatory disease, bile acid diarrhoea, medicines and malabsorption overwhelm otherwise adequate sphincter control and toilet warning time.
04
Functional toileting failure
Dementia, delirium, mobility, communication, inaccessible toilets and delayed assistance prevent continence despite preserved anorectal function and recognisable urge.
Pathophysiology
1
Colonic water and transit imbalance
Slow transit permits excessive water absorption and hard stool, whereas rapid transit produces urgency that exceeds sphincter reserve.
2
Rectal desensitisation
Chronic loading stretches the rectum, blunts urge and promotes retention, overflow and recurrent impaction after incomplete clearance.
3
Continence mechanism failure
Internal and external sphincters, rectal sensation, stool consistency and cognition must coordinate; impairment in several domains produces leakage.
4
Defaecatory dyssynergia
Inappropriate pelvic-floor contraction or failed relaxation obstructs evacuation despite urge and can make repeated laxative escalation ineffective.
5
Frailty feedback
Pain, embarrassment and commode dependence reduce eating, drinking and mobility, worsening stool consistency and toileting access.
Clinical features and red flags
Slow-transit constipation
Infrequent urge and stool with bloating and reduced bowel sounds suggests delayed colonic movement.
Defaecatory disorder
Prolonged straining, digital assistance and incomplete emptying despite softer stool suggests pelvic-floor dysfunction.
Overflow leakage
Small loose seepage around rectal loading accompanies distension, reduced sensation and incomplete evacuation.
Urge faecal incontinence
A strong warning occurs but loose stool or weak sphincter prevents timely toilet access.
Passive faecal incontinence
Stool is lost without awareness, suggesting sensory or internal-sphincter impairment.
Obstructive or neurological dangerRed flag
Vomiting, absent flatus, peritonism or new saddle and leg signs requires emergency assessment.
Red flags requiring action
Colicky pain, vomiting, marked distension and absent flatus requires urgent bowel-obstruction assessment before laxative escalation.
New retention or faecal incontinence with saddle change or bilateral leg weakness requires emergency spinal imaging.
Weight loss, iron-deficiency anaemia, rectal bleeding, mass or persistent change in bowel habit requires colorectal cancer investigation.
Fever, tachycardia, severe tenderness or bloody diarrhoea raises colitis, ischaemia or perforation concern and requires acute care.
Overflow diarrhoea around a large rectal load can cause dehydration, delirium and urinary retention despite apparently loose stool.
Perianal injury, unexplained bruising, fear of carers or deliberate withholding of toileting support raises safeguarding concern.
Investigations
01Bowel diary and Bristol stool formFirst step
Why
Define consistency, timing, leakage and treatment response.
Interpretation and limitations
Record complete movements, smears, urgency, food, fluid, medicines and toilet circumstances rather than frequency alone.
02Abdominal and digital rectal examination
Why
Detect loading, mass, anorectal disease and sphincter function.
Interpretation and limitations
Rectal stool supports impaction; an empty rectum does not exclude proximal loading and red flags still direct imaging.
03Targeted blood assessment
Why
Identify metabolic and systemic contributors.
Interpretation and limitations
Use FBC, renal, electrolytes, calcium, thyroid, inflammation or coeliac tests when symptoms and examination support them.
04Endoscopy or colorectal imaging
Why
Investigate bleeding, anaemia, weight loss or persistent change.
Interpretation and limitations
Choose urgent cancer or inflammatory pathways from red flags; routine imaging is unnecessary for stable uncomplicated constipation.
05Abdominal radiology
Why
Assess suspected obstruction, megacolon or severe proximal loading.
Interpretation and limitations
Use when clinical concern exists; a routine plain film is not a substitute for history and rectal examination.
06Specialist anorectal testing
Why
Characterise sphincter, sensation and evacuation dysfunction.
Interpretation and limitations
Manometry, endoanal ultrasound, defaecography or transit studies are selected after baseline care when they will change advanced treatment.
Small frequent loose leakage, abdominal discomfort and rectal loading indicate impaction rather than primary diarrhoea requiring antimotility treatment.
02
Primary diarrhoeal disease
High-volume loose stool, nocturnal symptoms, blood, inflammation or travel history requires infectious, inflammatory, microscopic or malabsorptive investigation.
03
Colorectal cancer
Persistent change, bleeding, anaemia, weight loss or mass requires urgent site-specific assessment even when constipation is longstanding.
04
Neurogenic bowel
Spinal disease, multiple sclerosis, Parkinsonism, stroke and autonomic neuropathy alter sensation, transit, sphincter and evacuation in different combinations.
05
Irritable bowel syndrome
Recurrent pain related to defaecation with altered stool can support IBS only after red flags and relevant older-onset disease are assessed.
Management
01First-line bowel assessmentSeparate loading, diarrhoea and access failureFirst stepFirst lineConstipation or faecal leakage is reported.+
1Describe stool, emptying, warning, leakage, diet, fluids, medicines, neurology and red flags and assess abdomen, perineum and rectum.
2Treat obstruction, spinal, inflammatory and cancer danger before routine bowel medicines.
3Agree a target stool and a practical food, fluid, movement, toileting, medicine and skin plan with a review date.
02Impaction routeClear fully, then prevent recurrenceRectal or clinically supported faecal loading causes pain, retention or overflow.+
1Exclude obstruction and perforation, assess hydration and identify the causal medicine, mobility and toileting factors.
2Use oral macrogol or location-appropriate rectal treatment under the current regimen and monitor stool, pain and fluid status.
3Confirm adequate clearance and begin titrated maintenance, scheduled toileting and follow-up before the cycle restarts.
03Faecal incontinence routeOptimise stool before advanced therapyLeakage persists after loading and red flags are addressed.+
1Treat loose-stool disease, regulate laxatives and establish predictable complete emptying and toilet access.
2When suitable, titrate low-dose loperamide toward soft formed stool and monitor constipation and abdominal symptoms.
3Refer persistent burden for pelvic-floor, biofeedback, irrigation, anorectal testing or surgical assessment according to phenotype.
04Community maintenance routeMake the bowel plan deliverableCognition, immobility or carers determine everyday bowel care.+
1EscalationWrite regular and rescue medicines, toileting timing, transfer support, target stool, skin care and escalation thresholds.
2Train carers in dignified prompting, administration and recognition of overflow, obstruction, dehydration and treatment overuse.
3Review the plan after illness, opioid change, reduced intake or functional transition and simplify where possible.
Key medicines and prescribing safety2 treatments · regimens, roles and cautions+
Osmotic stool softening for maintenance and oral disimpaction when the person can safely take the required fluid volume.
Macrogol 3350 with electrolytes
For constipation, use one sachet orally one to three times daily according to response. For confirmed faecal impaction in adults, dissolve eight sachets in one litre of water and consume within six hours daily for up to three days, only after obstruction is excluded.
Review swallowing, fluid and electrolyte tolerance, heart or kidney disease and worsening pain or vomiting; individual products differ and obstruction is a contraindication.
Preferred initial antidiarrhoeal option for selected faecal incontinence after loading, infection, inflammatory diarrhoea and contraindications are excluded.
Loperamide
For faecal incontinence with loose stool, NICE advises starting at 0.5 to 1 mg orally daily and titrating to the desired stool consistency, with a maximum total dose of 16 mg daily.
Avoid in hard or infrequent stool, acute bloody diarrhoea, active inflammatory colitis, ileus or suspected loading; excessive doses cause constipation, overflow and potentially serious cardiac toxicity.
Complications
01
Obstruction and perforation
Severe loading can cause stercoral ulceration, megarectum, volvulus, ischaemia, obstruction and perforation with peritonitis or sepsis.
02
Urinary and renal effects
A loaded rectum can impair bladder emptying, worsen incontinence and contribute to retention, infection and kidney injury.
03
Skin and pressure injury
Repeated stool exposure causes irritant dermatitis, infection and greater tissue damage over pressure-prone areas during prolonged immobility.
04
Delirium and appetite loss
Pain, retention, dehydration and faecal loading can present as confusion, reduced intake or functional decline during acute illness.
05
Isolation and carer crisis
Odour, unpredictability and labour-intensive cleansing restrict social activity and may make home care unsustainable without additional continence support.
Monitoring and follow-up
Use a bowel diary to track complete movements, Bristol form, leakage, urgency and rescue treatment.
During disimpaction, review pain, distension, vomiting, hydration, stool output and whether adequate clearance occurred.
Titrate maintenance medicines to soft formed stool and reduce them promptly if seepage represents treatment excess.
Inspect perianal and sacral skin and review cleansing, barrier care and pressure redistribution.
Assess appetite, fluid access, mobility, toileting posture, cognition and carer response after transitions.
Repeat colorectal, neurological or metabolic assessment when pattern changes or treatment unexpectedly fails.
Review social avoidance, sleep, dignity and carer workload alongside the episode count.
Special situations
Loose stool can mean blockage
Liquid leakage around a rectal mass is commonly mistaken for diarrhoea and worsened by antimotility treatment.
Daily does not mean complete
Small smears or fragments can occur every day while a large retained burden remains.
Fibre needs context
Bulking without adequate fluid or evacuation can increase discomfort and loading in selected frail patients.
The gastrocolic reflex is usable
Scheduled unhurried toileting after breakfast can align care with a normal physiological increase in colonic activity.
Skin treatment starts with stool control
Barrier products help, but predictable emptying and prompt gentle cleansing reduce repeated chemical injury.
Common pitfalls
01
Prescribing loperamide before excluding faecal loading.
02
Counting a smear as evidence that constipation has resolved.
03
Escalating fibre despite severe loading, poor fluid intake or dysphagia.
04
Starting oral disimpaction during suspected obstruction.
05
Ordering routine radiographs instead of an adequate bowel and rectal assessment.
06
Ignoring opioid initiation when designing prophylactic bowel care.
07
Using pads without treating stool consistency, access and skin exposure.
08
Writing as-needed laxative without dose, trigger, maximum and escalation instructions.