Constipation (Adults) ✅

💡 Constipation is common, usually benign, but always rule out bowel obstruction first 🚨 (Look for distension, vomiting, absent bowel sounds, hernial orifices, AXR findings). ⚠️ Avoid stimulant laxatives until obstruction excluded.

🌿 Introduction

• Rome IV criteria exist for academic diagnosis [Rome IV link], but most clinical practice is pragmatic.
• Diet: encourage hydration 🥛, mobility 🚶, and fibre (aim 30 g/day). Sorbitol-rich fruits (apples, pears, plums, grapes, raspberries, prunes) are especially helpful.
• Normal variation: stool frequency ranges from twice daily to twice weekly.

🧠 Anatomy & Physiology of Defaecation

• Colon: absorbs water, compacts stool.
• Rectum: storage; stretch receptors trigger defaecation reflex.
• Anus:
  • Internal sphincter: involuntary (smooth muscle)
  • External sphincter: voluntary (skeletal muscle)
• Puborectalis muscle: maintains anorectal angle for continence; relaxes during defaecation 💩.

🧾 Common Associations

• Childhood: Hirschsprung’s, cystic fibrosis
• Endocrine/metabolic: hypothyroidism, diabetes, hypercalcaemia, pregnancy
• Neurological: Parkinson’s, MS, spinal cord disease
• Structural: colon cancer, diverticulitis, haemorrhoids
• Medications 💊: opiates, antidepressants, diuretics, CCBs, iron, anticholinergics, NSAIDs, aluminium antacids
• Acute illness: immobility, dehydration

🚩 Red Flags (Investigate)

• PR bleeding, weight loss, family history of colorectal cancer
• Tenesmus, anorexia, night sweats, fever, ↑ inflammatory markers
• Abdominal mass, distension, or pain on PR exam

💊 Laxative Classes

• Bulk-forming: Ispaghula husk (Fybogel) – first-line, needs hydration; avoid in obstruction
• Osmotic: Macrogol (Movicol), Lactulose – for hard stools or opioid-induced constipation; may cause bloating/flatulence
• Stimulant: Senna, Bisacodyl, Sodium Picosulfate – poor propulsion; hydrolysed in colon; avoid if obstruction
• Stool softener: Docusate – adjunct, mild stimulant effect; useful in opioid constipation
• Prokinetic: Prucalopride – severe chronic constipation; 5HT4 agonist; caution in ischaemic heart disease
• Rectal: Phosphate/Microlax/Arachis oil enemas – disimpaction, rapid relief; avoid arachis oil in peanut allergy

🏥 In-Hospital Pearls

• Common triggers: immobility, dehydration, opiates/codeine
• Always examine rectum for hard stool
• Stop causative drugs if possible
• Escalation for disimpaction: Microlax → Phosphate → Arachis oil → Manual removal

💡 Toileting & Lifestyle Advice

• Encourage unhurried, regular routine ⏰
• Respond promptly to urge
• Support mobility and privacy
• Ensure supported seating for frail patients

⚠️ Laxative Cautions

• Avoid in suspected obstruction, perforation, paralytic ileus, toxic megacolon, active IBD flare
• Specific cautions:
  • Lactulose: galactosaemia
  • Bisacodyl: severe dehydration
  • Arachis oil enemas: peanut allergy
• Prolonged overuse → electrolyte imbalance (esp. hypokalaemia)

Cases - Constipation in Adults 🚽

• Case 1 - Functional Constipation 🥖: 45-year-old man, hard stools every 4–5 days, bloating, no red flags. Diet low in fibre. Management: Lifestyle modification (increase fibre, fluids, exercise); bulk-forming laxatives if required.
• Case 2 - Opioid-Induced Constipation 💊: 62-year-old woman on morphine, painful hard stools. Management: Regular stimulant + osmotic laxatives; consider peripherally acting opioid antagonist (e.g., naloxegol) if refractory.
• Case 3 - IBS-C 🌿: 35-year-old woman, alternating constipation and bloating, colonoscopy normal. Management: Dietary advice (low FODMAP), osmotic laxatives (PEG), linaclotide if refractory.
• Case 4 - Secondary Constipation (Hypothyroidism) 🦋: 70-year-old man, lethargy, weight gain, constipation. TFTs: TSH ↑, T4 ↓. Management: Thyroxine replacement; short-term laxatives if symptomatic.

Teaching Commentary 🧠

Constipation in adults is usually functional, but always consider: - Primary/functional (diet, IBS, slow transit) - Secondary (drugs, endocrine, metabolic, neurological) - Obstructive (colorectal cancer, strictures) ⚠️ Red flags: weight loss, anaemia, rectal bleeding, new onset >50 yrs → urgent colonoscopy Stepwise management: lifestyle → bulk-forming → osmotic → stimulant → specialist referral if refractory.