Chapter 10 — Faecal Incontinence, Constipation, and Pelvic-Floor Disorders

Purpose: incontinence and constipation are common, under-reported, and often treatable — ask, exclude the dangerous causes, then treat in steps before anyone considers surgery.

🎨 INFOGRAPHIC / VISUAL BLUEPRINT — CHAPTER 10

• Chapter colour palette: Plum (#86198F) header bar, Lilac Mist (#FDF4FF) panels, Aubergine (#4A044E) text.
• Hero graphic: A “continence balance”: stool consistency, sphincters, rectal reservoir and sensation, nerves, and toilet access on one side; leakage on the other. Beneath it, a Bristol stool chart strip and a diagram of dyssynergia (puborectalis squeezing instead of relaxing during a push).
• Icon set: Bristol chart, balance scale, pelvic-floor muscle sling, biofeedback screen, pill bottle with magnifier (medication review), toilet with footstool, red spine (cauda equina).
• Bedside aphorism banner: “Ask about leakage — patients rarely volunteer it. Firm stool and a trained pelvic floor fix more incontinence than surgery.”

1. Types of Faecal Incontinence

Table 10.1 — Faecal incontinence patterns

2. Assessment

• Ask directly — postpartum, older adults, diabetes, neurological disease, and after anal surgery or pelvic radiotherapy. Patients rarely volunteer incontinence.

• Characterise it: type (Table 10.1), frequency, stool consistency (Bristol type), urgency, pad use, and impact. Use a validated severity and quality-of-life measure (Wexner/Cleveland Clinic or St Mark’s score) (ASCRS 2023) [S].

• Screen for red flags: bleeding, change in bowel habit, weight loss, anaemia (Chapter 08); back pain, saddle numbness, or urinary retention (cauda equina — emergency).

• Review medications (Table 10.2) and obstetric, surgical, and radiation history.

• Examine: perineum (scars, gaping anus, dermatitis, prolapse or rectocele on straining), perianal sensation and the anal reflex, DRE at rest, on squeeze, and during a simulated push (paradoxical contraction suggests dyssynergia), and impaction or a mass.

3. Medications That Cause or Worsen Leakage and Constipation

Table 10.2 — Medication contributors

4. Stepped Conservative Management of Faecal Incontinence

Table 10.3 — Conservative measures

5. When to Request Specialist Tests

Table 10.4 — Tests and their indications

6. Chronic Constipation and Obstructed Defecation

• Define it (Rome IV): for at least 3 months, two or more of straining, lumpy or hard stools, incomplete evacuation, a sense of blockage, manual manoeuvres, or fewer than three bowel movements a week [C].

• Exclude secondary causes: medications (Table 10.2), hypothyroidism, hypercalcaemia, diabetes, Parkinson’s disease, multiple sclerosis, pregnancy, depression, and alarm features (Chapter 08).

• Treat in steps (AGA–ACG 2023): polyethylene glycol (macrogol), stimulant laxatives (bisacodyl, sodium picosulfate), and prescription agents (prucalopride, linaclotide, plecanatide, lubiprostone) have trial support; fibre, magnesium oxide, lactulose, and senna have lower-certainty evidence. Avoid magnesium in renal impairment.

• Opioid-induced constipation: osmotic or stimulant laxative from day 1; peripherally acting μ-opioid receptor antagonists (for example naloxegol, methylnaltrexone, naldemedine) if refractory [C].

• Obstructed defecation and dyssynergia: straining despite soft stool, incomplete evacuation, digitation or vaginal splinting; DRE shows paradoxical contraction or poor relaxation on pushing. Confirm with manometry and balloon expulsion; biofeedback is first-line (ACG 2021) [S]. A footstool can improve posture [U].

7. Rectal Prolapse, Solitary Rectal Ulcer Syndrome, and OASIS

• Full-thickness rectal prolapse: concentric folds, often in older women, frequently with incontinence or constipation. Refer to colorectal surgery; the operation (abdominal rectopexy or a perineal procedure) depends on fitness and symptoms. Incarceration → Chapter 02.

• Solitary rectal ulcer syndrome (SRUS): usually younger adults with straining, mucus, bleeding, and rectal pain; an ulcer or polypoid lesion often on the anterior rectal wall. Biopsy is essential because it can mimic cancer. Treat with fibre, stopping straining, and biofeedback (Chapter 15).

• Obstetric anal sphincter injury (OASIS): third- and fourth-degree tears. New postpartum incontinence or urgency needs early specialist follow-up, pelvic-floor physiotherapy, endoanal ultrasound where available, and counselling about future deliveries (RCOG Green-top 29) [C] (Chapter 13).

Algorithm 10.1 — Faecal incontinence and chronic constipation

[FAECAL INCONTINENCE OR CHRONIC CONSTIPATION]
|
+-- RED FLAGS FIRST
|   +-- New leak + back pain / saddle numbness / retention
|   |     -> RED: emergency MRI (cauda equina)
|   +-- Bleeding, weight loss, anaemia, bowel-habit change,
|   |   or mass -> YELLOW: colon evaluation (Chapter 08)
|   +-- Hard stool filling the rectum + watery leak
|         -> overflow: disimpact first (Chapter 06)
|
+-- Characterise: passive / urge / mixed / seepage;
|   Bristol type; obstetric and surgical history;
|   medication review; DRE (tone, squeeze, push)
|
+-- STEP 1 (everyone): normalise stool (fibre; loperamide
|   if loose and impaction/infection excluded; laxatives
|   if constipated); stop culprit drugs; timed toileting;
|   skin barrier; pads or plugs
|
+-- STEP 2 (not better after 4-8 weeks):
|   pelvic-floor physiotherapy + biofeedback
|
+-- STEP 3 (still not better, sphincter injury, prolapse,
    or suspected dyssynergia):
      -> colorectal / pelvic-floor referral: manometry,
         balloon expulsion, endoanal ultrasound,
         defecography

8. Continence-Focused Referral Template

Table 10.5 — Continence referral template

9. Dangerous Mimics

Table 10.6 — Continence and constipation mimics

10. Role-Targeted Action Boxes

🚑 ER DOCTOR ACTION BOX

• New incontinence with back pain or neurological symptoms = cauda equina until proven otherwise: emergency MRI.
• Constipation with vomiting, distension, or abdominal pain suggests obstruction, volvulus, pseudo-obstruction, or stercoral perforation — image and involve surgery (Chapter 15).
• Patients on clozapine with constipation and abdominal pain or distension need urgent assessment (FDA 2020).

🩺 FAMILY MEDICINE / GP CLINIC BOX

• Ask the continence question routinely after childbirth, in older adults, and in people with diabetes or previous anal surgery.
• Work through the steps: stool consistency, medication review, toileting, skin care, then pelvic-floor physiotherapy and biofeedback before specialist referral.
• Use the referral template — it saves a clinic visit and speeds up testing.

🏥 ER & WARD NURSE CARE AND SBAR BOX

• Prevent incontinence-associated dermatitis: cleanse gently, pat dry, apply a barrier, and change pads promptly.
• Keep a Bristol stool chart and a toileting schedule; report no bowel movement for 3 days, new watery leakage, or abdominal distension.
• Protect dignity and assess pressure-injury risk in bed-bound patients.

💊 CROSS-SPECIALTY PRESCRIBING TRAP

• Loperamide in overflow, C. difficile, or dysentery can be dangerous — examine and test first.
• Stimulant laxatives in suspected bowel obstruction can cause perforation.
• Magnesium-containing laxatives in renal impairment risk hypermagnesaemia; sodium phosphate enemas in high-risk patients (Chapter 06).
• Anticholinergic burden in older adults worsens constipation and cognition.

⛔ NEVER DO THIS

• Never give an antidiarrhoeal to a high-risk patient before a DRE.
• Never label faecal incontinence as “normal ageing”.
• Never refer for sphincter surgery without specialist anorectal physiology.
• Never prescribe a stimulant laxative when bowel obstruction is suspected.

📝 COMMON DOCUMENTATION ERROR

• “Incontinent of faeces” without type, frequency, Bristol type, DRE findings, medication review, and neurological screen.
• Constipation managed for months without documenting alarm features or a DRE.

📨 REFERRAL URGENCY BOX

The Patient in Front of You — Chapter 10 Mini-Case

🧑‍⚕️ THE PATIENT IN FRONT OF YOU

A 58-year-old woman with type 2 diabetes on metformin reports urgency and loose stools with leakage three times a week, which she has never mentioned before. She had three vaginal deliveries, one with forceps and a “bad tear”. There is no bleeding, weight loss, back pain, or numbness. On DRE resting tone is reasonable but voluntary squeeze is weak, with a thin anterior perineum.

Step 1 Classify: urge incontinence, suggesting an external sphincter injury (probable old OASIS), worsened by loose stool.

Step 2 Look for contributors: metformin-related loose stool; check HbA1c and consider diabetic autonomic neuropathy.

Step 3 Step 1: discuss modified-release metformin or alternatives with the diabetes team; fibre titration; loperamide before outings once infection is excluded; skin barrier; validated score recorded.

Step 4 Step 2 and referral: pelvic-floor physiotherapy and biofeedback; referral for endoanal ultrasound and manometry using the template.

Board-Style Question — Chapter 10

A 45-year-old woman reports years of straining, a sense of incomplete evacuation, and needing to press on the perineum to empty her bowel, although her stools are soft. On DRE, the anal sphincter and puborectalis tighten when she is asked to push. Colonoscopy is normal. What is the best next step?

• A. Escalate stimulant laxatives to daily maximum doses
• B. Anorectal manometry with a balloon expulsion test, followed by biofeedback therapy if dyssynergia is confirmed
• C. Refer for subtotal colectomy
• D. Start regular loperamide

Answer and explanation

• ❌ A Laxatives do not correct a failure of pelvic-floor relaxation and may cause urgency without improving evacuation.
• ✅ B Correct. Paradoxical contraction on pushing with soft stool and digitation suggests dyssynergic defecation. Confirm with manometry and balloon expulsion; biofeedback is first-line treatment (ACG 2021).
• ❌ C Colectomy is not indicated for obstructed defecation and can worsen symptoms.
• ❌ D Loperamide would worsen constipation.

Ten-Item Rapid Revision Checklist — Chapter 10

• 01 I ask about incontinence routinely in at-risk groups.
• 02 I classify incontinence as passive, urge, mixed, overflow, or seepage.
• 03 I screen for cauda equina red flags and colorectal alarm features.
• 04 I review medications, including metformin, opioids, anticholinergics, and clozapine.
• 05 I examine tone, squeeze, and the push manoeuvre on DRE.
• 06 I normalise stool consistency before anything else.
• 07 I use loperamide only after excluding impaction and infection.
• 08 I refer for pelvic-floor physiotherapy and biofeedback before surgery.
• 09 I know when to request manometry, endoanal ultrasound, and defecography.
• 10 I use the continence referral template.

Five Most Dangerous Mistakes — Chapter 10

1. ⚠️ Missing cauda equina syndrome in a patient with new incontinence.
2. ⚠️ Prescribing loperamide for overflow from impaction.
3. ⚠️ Escalating laxatives for dyssynergia instead of arranging biofeedback.
4. ⚠️ Ignoring severe constipation in a patient taking clozapine.
5. ⚠️ Treating postpartum incontinence as normal and missing an OASIS defect.

Suggested Figure and Table Captions for the Medical Illustrator — Chapter 10

• Figure 10.1. The continence balance: stool consistency, sphincters, reservoir, sensation, nerves, and access.
• Figure 10.2. Bristol stool form scale.
• Figure 10.3. Normal defecation versus dyssynergia (paradoxical puborectalis contraction).
• Figure 10.4. Biofeedback session set-up.
• Table 10.1. Faecal incontinence patterns.
• Table 10.2. Medication contributors.
• Table 10.3. Conservative measures.
• Table 10.4. Tests and their indications.
• Table 10.5. Continence referral template.
• Table 10.6. Continence and constipation mimics.
• Algorithm 10.1. Faecal incontinence and chronic constipation.