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📚 EXAM NOTES: OESOPHAGUS, INTESTINAL OBSTRUCTION & PRURITUS ANI

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🔴 REFLUX OESOPHAGITIS (GORD)

Key Definitions

• Gastro-oesophageal reflux = regurgitation of gastric contents into oesophagus
• GORD = loss of LOS competence leading to pathological reflux
• Normal reflux: only 20 min/day in erect posture

Pathophysiology - Key Points

• LOS (Lower Oesophageal Sphincter) = most important factor in gastro-oesophageal competence
• TLOSRs (Transient LOS Relaxations) = main mechanism in early GORD
• In severe GORD: LOS loses basal tone + shorter intra-abdominal length
• Loss of LOS competence = GORD
• DeMeester clarified LOS competence; Dent discovered TLOSRs

Aetiology of GORD

Symptoms of Reflux Oesophagitis (3 Groups)

• Other symptoms: Flatulent dyspepsia, respiratory symptoms (aspiration pneumonia, lung abscess, bronchiectasis)

Grades of Oesophagoscopy (Oesophagitis Grading)

• Barrett's oesophagus: Columnar epithelium >3 cm above GOJ = precursor of adenocarcinoma of distal oesophagus

Diagnosis

• Barium swallow + upper oesophageal radiograph - first investigation; only 50% show reflux
• Oesophageal function tests - Acid reflux test most informative
• Oesophagoscopy - always indicated; grades 0-4
• Flexible oesophagoscopy - has replaced rigid; no GA required; outpatient

Complications of GORD (8 - HIGH YIELD)

1. Bleeding
2. Shortening of oesophagus
3. Stricture
4. Barrett's oesophagus
5. Oesophageal ulcer penetration/perforation
6. Respiratory aspiration
7. Schatzki's ring (contraction ring of lower oesophagus)
8. Adenocarcinoma

Treatment

Medical Treatment (6 months trial)

• Sleep with head end elevated on 6-inch blocks
• No food just before bedtime
• Avoid stooping
• Avoid smoking, alcohol, tea, coffee
• Antacids 1 hour after meals + bedtime; H2 antagonists; PPIs (omeprazole, lansoprazole, pantoprazole) - most effective
• Metoclopramide - increases oesophageal peristalsis + gastric emptying
• Reduce weight; small meals; avoid tight garments
• Drugs to AVOID: Muscle relaxants, anticholinergics, tranquilizers

Surgical Indications

1. Symptoms not controlled by vigorous medical therapy
2. Symptoms recur soon after stopping medical treatment
3. Intractable oesophagitis
4. Ulceration or stricture
5. High grade dysphagia or metaplasia to columnar epithelium

• Operation: Anti-reflux operation = Nissen Fundoplication (restoration of intra-abdominal oesophageal segment + tube-like distal oesophagus)

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🔵 ACHALASIA OF THE OESOPHAGUS

Key Historical Facts (HIGH YIELD)

• Discovered: 1674 by Thomas Willis
• Properly described: 1915 by Hurst
• Term 'achalasia' = Greek for "failure of relaxation"
• In achalasia: peristalsis is absent/feeble + LOS fails to relax

Pathophysiology

• Degeneration/absence of ganglion cells of Auerbach's plexus = neurogenic basis (main cause)
• In 30% cases: degeneration absent → extraoesophageal cause
• Achalasia vs Hirschsprung's: Achalasia = few ganglion cells in dilated oesophagus; Hirschsprung's = normal ganglion cells proximal to constricted aganglion segment

Causes

• Emotional stress
• External compression/trauma
• Chagas' disease (Trypanosoma Cruzi)
• Infection

Clinical Features (3 main)

1. Dysphagia - begins with cold > warm foods; liquids pass easier initially; worsens to solids
2. Regurgitation - characteristic at night; no sour taste (unlike GORD)
3. Weight loss

• Pain: retrosternal; may mimic angina; disappears when oesophagus dilates
• 5-10% cases: associated carcinoma (premalignant); squamous cell carcinoma type; arises in middle-third

Diagnosis

Treatment

Medical

• Calcium channel antagonists (nifedipine) - short-term; sublingual; not permanent
• Botulinum toxin - endoscopic injection into LOS; interferes with cholinergic excitatory neural activity

Mechanical Dilatation

• Balloon dilatation to disrupt circular muscle fibres
• Balloons: 30-40 mm diameter, inserted over guide wire
• Complication: Oesophageal perforation (<0.5%)
• Curative dilatation: 65-85% of cases

Surgical - Oesophagomyotomy

• Originally by Heller (1914) - transabdominally, anterior + posterior walls
• Modern = Modification of Heller's operation - thoracic approach + myotomy on anterior wall only
• Incision: 7-10 cm longitudinal through all muscle layers of distal oesophagus; extends to stomach within 1 cm distally
• Good result in >90% cases on 10-year follow-up
• 3% develop GORD post-myotomy → prophylactic anti-reflux procedure
• Laparoscopic Heller's myotomy - now used successfully in >90% cases

Treatment of Choice Debate

• Most surgeons: oesophagomyotomy = treatment of choice
• Others: try hydrostatic dilatation first (cures 65%) → surgery if failed

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🟡 DYSPHAGIA - CAUSES (HIGH YIELD TABLE)

Definition

• Dysphagia = difficulty in swallowing
• Odynophagia = painful swallowing (especially severe in chemical injury; burning in reflux oesophagitis)
• Types: Functional (neurological) or Physical (pressure on lumen/foreign body)

Causes of Dysphagia

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🟢 INTESTINAL OBSTRUCTION

Classification

Aetiology

A. Mechanical Obstruction

• Meconium, bezoars (trichobezoar/phytobezoar), gallstones, polypoid tumour, bowel, intussusception, impacted barium/worms

• Congenital: Atresia/stenosis, Hirschsprung's, Meckel's, imperforate anus, diverticuli
• Traumatic
• Inflammatory: Crohn's, ulcerative colitis (rare), diverticulitis
• Neoplastic: small/large bowel tumours
• Miscellaneous: radiation therapy, iatrogenic stricture, potassium-induced stricture

• Adhesive band constriction = leading cause of small intestinal obstruction
• External hernia = second most common (inguinal, femoral, umbilical, incisional)
• Volvulus
• Haematomas/abscess, neoplasms outside bowel, annular pancreas

B. Paralytic Ileus Causes

Pathology

Bowel Motility

• Above obstruction: vigorous peristalsis (2-6 days) → then flaccid/paralysed
• Below obstruction: normal initially → immobile, contracted, pale

Intestinal Gas Composition (HIGH YIELD)

• Swallowed air = most important source of intestinal gas

Fluid & Electrolyte Imbalance

• Daily digestive juices: Saliva 1500ml, gastric juice 2500ml, bile + pancreatic juice 1000ml, intestinal juice 3000ml = ~8000ml/day
• Proximal obstruction: more vomiting → loss of water, sodium, chloride, hydrogen, potassium → hypochloraemia, hypokalaemia, metabolic alkalosis
• Dehydration → oliguria, haemoconcentration, azotaemia, low CVP, hypotension, hypovolaemic shock

Bacterial Proliferation

• Rapid proliferation during obstruction
• In simple mechanical small intestinal obstruction: bacteria probably play no role in ill effects
• In strangulation: bacteria + toxins pass through bowel wall → peritoneal cavity

Strangulation Features

• Venous return impaired → arterial supply continues → greatest distension
• Colour change: purple → black → gangrene
• Onset of gangrene = when venous return is completely occluded
• Transmigration of bacteria + toxins → shock

Clinical Features

4 Cardinal Symptoms

1. Abdominal pain - colicky, cramping, synchronous with hyperperistalsis
2. Vomiting - early (reflex) then actual; faeculent in distal obstruction
3. Constipation - failure to pass flatus/faeces (becomes evident only after bowel distal to obstruction is emptied)
4. Abdominal distension - late in high small bowel; early in colon obstruction

Pain Characteristics by Level

Vomiting Characteristics

• High obstruction: frequent, copious, may relieve distension
• Low small bowel: less frequent, faeculent
• Colon obstruction with competent ileocaecal valve: vomiting absent until small bowel retrograde involvement

Physical Examination

• All hernial orifices must be inspected/palpated - may diagnose obscure hernias
• Rectal examination mandatory - mass in lumen/outside lumen gives clue to diagnosis
• Sigmoidoscopy if colonic obstruction suspected

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🟣 PRURITUS ANI

Definition

• Intractable itching around the anus

Surgical Causes (HIGH YIELD LIST)

1. Prolapsing haemorrhoid
2. Anal fissure
3. Fistula-in-ano
4. Ectropion
5. Condyloma acuminata
6. Colloid carcinoma of rectum
7. Carcinoma of anal canal
8. Basal cell carcinoma of anal canal
9. Malignant melanoma of anal canal

Other (Non-Surgical) Causes

Treatment

• Treat underlying cause
• Idiopathic: Hygienic measures; keep anus clean + dry
• Hydrocortisone 0.5% - applied locally for temporary relief
• Topical fungicides - symptomatic control
• Straping buttocks apart - keeps perianal region dry; considerable role in idiopathic pruritus ani

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⚡ HIGH-YIELD ONE-LINERS FOR MCQs

• GORD most common cause in western countries = replacing peptic ulcer disease
• Scleroderma = most common systemic collagen disease causing reflux oesophagitis
• Barrett's oesophagus = columnar epithelium >3 cm above GOJ = precursor of adenocarcinoma
• Achalasia discovered: Thomas Willis 1674; described by Hurst 1915
• Bird-beak sign = achalasia on barium swallow
• Best investigation for achalasia = Oesophageal manometry
• Carcinoma in achalasia = 5-10%; squamous cell; middle-third
• Heller's myotomy = treatment of choice for achalasia; >90% success
• Laparoscopic Heller's = now used in >90% cases
• Adhesive bands = leading cause of small intestinal obstruction
• External hernia = second most common cause of mechanical small bowel obstruction
• Intestinal gas composition: Nitrogen 70% (most) → from swallowed air (most important source)
• Continuous severe pain without quiescent period = strangulation
• Absent bowel sounds at a region = strangulation at that region
• Faeculent vomiting = distal small bowel obstruction (large bacterial population)
• Idiopathic pruritus ani = constitutes largest group
• Paterson-Kelly syndrome = pharyngeal + oesophageal dysphagia
• Dysphagia lusoria = outside-wall cause of oesophageal dysphagia