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📋 EXAM NOTES: COLORECTAL & ANORECTAL CONDITIONS

(Source: A Concise Textbook of Surgery)

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1. ULCERATIVE COLITIS

Aetiology

• Cause: UNKNOWN - main theories:
  • Infective - no definite pathogen proven (Chlamydia, CMV, Clostridial toxin - all unproven)
  • Nutritional - fruitless attempts to identify
  • Psychosomatic - personality factors present before onset; colectomy improves morbidity
  • Immunological - lymphocytes cytotoxic to colon; T & B cell populations altered; IgG antibodies may play role; milk-free diet benefits some

Key Immunological Points

• Autoantibodies to colon demonstrated
• Autoantibodies do NOT correlate with severity/course
• Cross-reaction between colonic epithelium and E. coli bacteria (important!)

Pathology

• Confined to mucosal and submucosal layers only
• Rectum most frequently involved (90-95%)
• Disease is always in continuity - NO skip lesions (unlike Crohn's)
• Terminal ileum involved in only 10% (back-wash ileitis)

Macroscopic Features

• Superficial fissures, small regular pseudopolyps
• Irregular, shallow, linear anastomosing ulcers
• Islands of swollen mucosa = pseudopolyps (characteristic)
• Serosa normal for long time
• Fistulas (except perianal) are RARE (unlike Crohn's)
• Bowel greatly shortened in advanced cases

Microscopic Features

• Diagnosis by biopsy
• Earliest lesion: crypt abscesses (neutrophils pass into lining cells of crypts of Lieberkuhn)
• Crypt abscesses rupture → form tiny ulcers
• Chronic phase: lymphocytes, plasma cells, macrophages, eosinophils, mast cells
• Normal mucosa between ulcers = pseudopolyp (granulation tissue inflammation)

Clinical Types (3 forms)

Special Investigations

• Loss of haustration (early - due to paralysis of muscularis mucosa)
• Irregularities of colon wall = small ulcerations
• Pseudopolyps (as disease progresses)
• Rigid contracted tube appearance (advanced)
• Yearly barium + colonoscopy after 10 years (due to rising malignancy risk)
• Straight X-ray: toxic megacolon = remarkable dilatation with air inside; free air = perforation

• Rectum involved in 90-95% cases
• Mucosa: erythematous, granular, friable
• Superficial ulceration visible
• Cobblestone/deep linear ulcers = Crohn's disease (NOT UC)
• Pseudopolyposis may be seen
• ~50% distribution proximal to splenic flexure

Complications of UC

• (i) Haemorrhage
• (ii) Perforation - free or with abscess/fistula
• (iii) Stricture with partial obstruction
• (iv) Perianal/perirectal abscess and fistulas
• (v) Toxic megacolon ⭐
• (vi) Carcinoma of colon ⭐

Toxic Megacolon

• Manifestation of fulminant colitis
• Cause of toxic dilatation = UNKNOWN (necrotising inflammation of smooth muscle)
• Contributing factors: hypocalcaemia, hypoproteinaemia, anticholinergic drugs
• Diagnosis: patient with acute colitis + sudden decrease in stools + bloody rectal discharge + toxic + febrile + progressive abdominal distension + absent bowel sounds + gaseous distension of transverse colon
• Treatment: antibiotics + intestinal decompression + electrolyte correction + blood, albumin transfusions + IV alimentation

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2. HAEMORRHOIDS (PILES)

Definition

• Dilated veins within anal canal in subepithelial region formed by radicles of superior, middle and inferior rectal veins

Types

Aetiology of Internal Haemorrhoids

• Hereditary (same family)
• Anatomical: absence of valves in superior haemorrhoidal veins; veins pass through rectal musculature 10 cm above anus; radicles unsupported in submucosa
• Exciting causes: straining at stool (Parks theory) - dilates venous plexus
• Physiological: corpus cavernosum recti - arteriovenous communication; hyperplasia produces varicosity
• Diet: low roughage 'Western' diet
• Secondary: carcinoma rectum, pregnancy, chronic constipation, difficulty in micturition (urethral stricture/prostate), portal hypertension

Three Primary Haemorrhoids

• Located at 3, 7, and 11 O'clock positions (lithotomy)
• Each contains terminal divisions of superior rectal artery and vein

Degrees of Prolapse

• 1st Degree - Does NOT come out of anus
• 2nd Degree - Come out during defaecation, reduce spontaneously
• 3rd Degree - Come out during defaecation, need manual reduction
• 4th Degree - Permanently prolapsed

Clinical Features

1. Bleeding - bright red, PAINLESS, occurs with defaecation (splashes in pan); principal/earliest symptom
2. Prolapse - later symptom
3. Pain - NOT characteristic UNLESS thrombosis or associated fissure-in-ano
4. Mucous discharge - symptom of prolapsed haemorrhoids; causes pruritus ani
5. Anaemia - in long-standing cases (persistent bleeding)

Key Examination Points

• Digital examination CANNOT feel uncomplicated internal pile unless thrombosed
• Proctoscopy reveals internal pile
• Sentinel pile = associated with fissure-in-ano (NOT haemorrhoid)

Complications

• (i) Bleeding
• (ii) Thrombosis
• (iii) Strangulation - 2nd degree most often; "acute attack of piles"
• (iv) Gangrene - arterial supply constricted
• (v) Fibrosis
• (vi) Suppuration (very rare)
• (vii) Pylephlebitis (portal pyaemia) - theoretical; treated with antibiotics

Treatment

• Method of choice for small vascular haemorrhoids (1st degree)
• Sclerosant: 5% phenol in almond/arachis oil with 1-2 ml menthol (Albright's solution)
• Injected into submucosa at pedicle
• Cure rate 95%, recurrence 15% within 3 years
• Contraindications: prolapsed piles, arterial piles, presence of infection

• Ideal for 1st and small 2nd degree internal haemorrhoids
• Band placed at least 1 cm above dentate line
• Haemorrhoid necroses in 24-48 hours, sloughs in ~7 days
• Disadvantage: pain in first 24-48 hours; secondary haemorrhage

• Temperature -160°C for 3 minutes at pedicle
• Pain free (great advantage)
• Disadvantage: profuse watery discharge for 2-4 weeks
• Healing complete in 4-6 weeks
• Little efficacy if prolapse present

• Disrupts tight 'pecten bands'
• 3 fingers of both hands inserted
• Ideal for fissure-in-ano; also for early haemorrhoids
• Significant incontinence risk (especially elderly with pelvic floor problems)

• For large 3rd degree haemorrhoids with associated tags
• Ligature and Excision Method (most widely used)
• Lithotomy position; V-cut on skin; haemorrhoids fixed to muscularis with stout ligature (silk/catgut)
• Anal mucosa bridges between haemorhhoidal wounds (to prevent stenosis)

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3. FISSURE-IN-ANO

Definition & Key Facts

• Very common and painful condition
• Fissures occur most commonly in midline posteriorly (90%)
• Much less commonly anteriorly (10%)
• Females: slightly more common in midline posteriorly (60:40 anterior-posterior ratio)
• Anterior fissures in females explained by foetal head on anterior wall during delivery

Aetiology

• Predominantly posterior midline location explained by:
  • (a) Posterior angulation of anal canal
  • (b) Relative fixation of anal canal posteriorly
  • (c) Divergence of external sphincter fibres posteriorly
  • (d) Elliptical shape of anal canal
• Constipation - most common aetiological factor
• Spasm of internal sphincter
• Hard motion during haemorrhoidectomy
• Anal stenosis

• (i) Ulcerative colitis
• (ii) Crohn's disease
• (iii) Syphilis
• (iv) Tuberculosis

Pathology

• Fissure starts at dentate line (skin of anal canal = most painful area)
• Fissure lies in sensitive skin → pain is chief symptom

Types

• Deep canoe-shaped ulcer with thick oedematous margins
• At upper end: hypertrophied anal papilla
• At lower end: sentinel pile/tag (skin tag)
• Base: scar tissue + internal sphincter muscle
• Internal sphincter spasm always present

Clinical Features

• More common in women
• Age: 30-50 years
• Constipated hard stool → acute tear → ACUTE fissure = spasm + pain during defaecation + streaks of blood in paper
• Untreated → CHRONIC fissure = deep undermined ulcer + hypertrophied papilla + sentinel pile
• Pain + Bleeding = two main symptoms
  • Pain: starting with defaecation, lasting 1+ hour; described as sharp, biting, burning
  • Bleeding: streaks on outside of stool or on tissue
• Haemorrhoids associated in 1st and 2nd degrees are usually PAINLESS

Examination

• Tightly closed puckered anus = pathognomonic
• Sentinel skin tag may not be present
• Gentle separation of anal margins → lower end of fissure inspected
• Chronic fissure: palpable by digital examination
• Acute fissure: NOT palpable
• Proctoscopy not possible without GA in acute cases

Differential Diagnosis

1. Multiple fissures - think AIDS (HIV test!)
2. Carcinoma of anus - biopsy under GA
3. Tuberculous ulcer - undermined edge
4. Proctalgia fugax - severe pain from rectum at irregular intervals; cramp-like; disappears spontaneously; associated with stress/anxiety

Treatment

• Pain medication before anticipated bowel movement
• Stool softeners
• Glyceryl trinitrate (GTN) ointment - nitric oxide donor → relaxes internal sphincter; heals majority; side effect = headache
• Calcium channel blockers (e.g. diltiazem) - later on
• 5% xylocaine ointment with fine nozzle into canal
• Self dilatation with St. Marks dilator

• Simplest method; under GA; lithotomy position
• Index + middle fingers of both hands inserted; maximal dilation
• 1 patient can go home same day
• Warning: incontinence may occur (10%)
• If excessive fibrosis + skin tag → operation more appropriate

• Lithotomy position, GA
• Internal sphincter fibres divided; floor of fissure made smooth
• Sentinel pile excised if present
• Postop: liquid diet 2 days, bowel moved 3rd day, hip bath
• Convalescent period: 7-10 days (occasional persistent mucous discharge)

• Internal sphincter divided away from fissure (lateral position)
• Convalescent period: 1 day (ideal method for early cases)
• Disadvantage: biopsy of ulcer/excision NOT possible; 10-12% swelling/incontinence

• Edges excised + mobilised as full thickness skin flap
• Slid over fissure and sutured
• No chance of incontinence (internal sphincter not damaged)

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4. FISTULA-IN-ANO

Definition

• Inflammatory track with:
  • External opening (secondary) in perianal skin
  • Internal opening (primary) in anal canal or rectum
  • Lined by unhealthy granulation and fibrous tissue

Cause

• Usually originates from perianal abscess in intersphincteric space
• Anal gland infection → duct blockage → abscess → fistula
• Other causes: Ulcerative colitis, Crohn's, Tuberculosis, Colloid carcinoma of rectum, Bilharziasis, Lymphogranuloma inguinale

Classification

• (i) Subcutaneous
• (ii) Submucous
• (iii) Intersphincteric
• (iv) Transphincteric
• (v) Suprasphincteric

• (i) Extrasphincteric
• (ii) Transphincteric
• (iii) Pelvi-rectal fistula
• Low level fistula can be laid open safely
• High level fistula = risk of permanent incontinence

Goodsall's Rule (⭐ Exam Favourite)

• Imaginary transverse line drawn through midpoint of anus
• External opening POSTERIOR to this line → track curves posteriorly → internal opening in posterior midline
• External opening ANTERIOR to this line → track runs straight → internal opening directly anterior
• Exception: if anterior external opening >1.75 inches (3.75 cm) from anus → track curves posteriorly, ends in posterior midline

Clinical Features

• History of perianal abscess → ruptured/incised → non-healing discharging sinus
• External opening within 3.7 cm of anus
• Granulation tissue may be seen
• Tuberculosis: multiple fistulae; solitary fistula with watery discharge + discoloured surrounding skin = strongly suggest TB

Investigations

• Rectal examination (EXTREMELY IMPORTANT): internal opening palpable; above anorectal ring = high fistula
• Proctoscopy - visualise internal opening
• Lipiodol Injection - into external opening prior to X-ray; shows track (but may cause recrudescence of inflammation - utility in doubt)
• Chest X-ray - to exclude TB (most serious complication = carcinoma)

Treatment

• Fistulotomy (lay open): lithotomy position; bidiagital examination under GA; probe inserted through external opening; track laid open; fibrous tissue scraped with Volkmann spoon
• Healing by granulation tissue

• Mostly secondary to Crohn's/UC/carcinoma/foreign body
• Treat primary condition first
• Do NOT lay open (will cause incontinence)

• Lower track opened as usual
• Upper track scraped with Volkmann spoon
• OR: Seton passed around deeper part

• Heavy black silk or rubber band passed around deeper part including sphincter fibres
• Silk tied loosely outside for 2 weeks → stimulates fibrosis
• After 6 weeks: remaining part of track (with sphincter fibres) excised
• Fibrosis from procedure prevents retraction of sphincter → no incontinence
• This is Gabriel's two-stage operation
• Alternatively: stainless steel wire (cutting seton) gradually tightened → slowly cuts through sphincter

• Fistulotomy

• Posterior midline internal sphincterotomy + laying open deep part of fistula track
• Lateral tracks excised = Hanley's operation

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5. ANORECTAL ABSCESSES

Definition

• Abscesses around lower rectum and anal canal
• Important as they often culminate in fistula-in-ano

Causative Organisms

• Usually E. coli
• Less commonly: Staphylococcus aureus, Bacteroids, Streptococcus, B. Proteus
• 90% start as infection of anal gland
• 10% blood-borne (e.g., cutaneous boil extension)

Classification

1. Perianal (60%) - most common
2. Ischiorectal (30%) - second most common
3. Submucous
4. Pelvi-rectal

1. Perianal Abscess

• Inflammation of anal gland → pus collects within internal sphincter → paves way between internal sphincter and conjoined longitudinal muscle → superficial in perianal region
• Also: infection of thrombosed external pile

• Throbbing pain around anus (exaggerated during defaecation)
• Constitutional symptoms (fever, headache)
• Angry lump at anal margin
• Tender cystic lump felt by finger in anal canal just below dentate line

• Incision and drainage immediately under antibiotic cover
• Bold cruciate incision on most prominent part (under GA)
• Open abscess cavity adequately; Sinus forceps to break loculi
• Internal sphincter separated from mucosa; lower part of internal sphincter incised (to prevent fistula formation)
• Skin edges incised to keep wound wide open
• Healing by granulation tissue

• Rupture into anal canal
• Rupture to exterior (causing fissure-in-ano)
• Pass laterally through external sphincter → ischiorectal abscess

2. Ischiorectal Abscess

• Extension of anal gland inflammation laterally through external sphincter (commonest)
• Blood/lymph infection
• Penetrating injury
• Extension from pelvi-rectal abscess through hiatus of Schwalbe

• Ischiorectal fossa: full of fat, poorly vascularised → infection continues long time
• Connected to opposite side posteriorly → can spread to opposite side if not treated early → Horseshoe abscess

• Acute pain by side of anus (exaggerated during defaecation)
• Tender brawny indurated swelling in ischiorectal fossa
• Constitutional symptoms + fever

• Cruciate incision on most prominent part under GA
• Incisions extend beyond edge of swelling
• Adequate skin roof excised
• Cavity explored with finger; septa divided
• Necrotic tissue removed; cavity packed with gauze
• T-bandage applied
• If extension from pelvirectal abscess: hiatus of Schwalbe enlarged + cavity above curetted

3. Submucous Abscess

• Situated just deep to mucous membrane above dentate line
• Usually from anal gland spread or after injection of haemorrhoids
• Drained by small incision by stretching anus or by proctoscope

4. Pelvi-rectal Abscess

• Above levator ani (pelvic floor), below pelvic peritoneum
• Causes: appendicitis, diverticulitis, salpingitis, parametritis
• Also from ischiorectal abscess (overenthusiastic attempt to drain through ischiorectal fossa)
• Sequelae: if untreated → burst into rectum OR through hiatus of Schwalbe into ischiorectal fossa
• Treatment: drainage through fornix of vagina OR through anterior wall of rectum

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