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Gastro Exam

Perianal Inspection

October 29th, 2020

Perianal Rash

  • Look For

  • Erythematous patches or plaques over the perianal area.
  • Causes of Perianal Rash

  • Dermatoses - contact dermatitis, atopic dermatitis, seborrhoeic dermatitis, psoriasis, vitiligo
  • Infection - Staphylococcus, Streptococcus, Corynebacterium, Candida, pinworm
  • Crohn's disease
  • Extramammary Paget's disease
  • Dysplasia secondary to HPV

Perianal Blood

  • Look For

  • Bright red blood over the perianal area.
  • Causes of Perianal Blood

  • Perianal

  • Haemorrhoids
  • Anal tumour - squamous cell carcinoma, basal cell carcinoma, Paget's disease
  • Fistula in ano
  • Fissure in ano
  • Colorectal

  • Colorectal cancer
  • Colorectal polyp
  • Colitis - IBD, infection, diverticulitis
  • Radiation proctitis / colitis
  • Angiodysplasia
  • Trauma

Fissure in Ano

  • Look For

  • Tears in the anal opening.
  • Causes of Fissure in Ano

  • Constipation - large / hard stool, straining
  • Chronic diarrhoea
  • Crohn's disease
  • Childbirth
  • Infection - abscess, syphilis, tuberculosis, herpes
  • Haemorrhoids
  • Anal tumour

Perianal Sinus / Fistula

  • Look For

  • One or more openings in the perianal area that may be associated with discharge of blood, pus or faecal material.
  • Significance

  • Pilonidal sinus: a blind-ending tract opening from the anus, which may be associated with an underlying cyst.Infected damaged hair follicle
  • Fistula in ano: an abnormal connection between the perianal area and the anus, rectum, vagina or other pelvic organ.Anorectal abscess, Crohn's disease, diverticulitis, tumour, tuberculosis

Perianal Masses

  • Look For

  • A mass around or protruding from the anus.
  • Causes of Perianal Mass

  • Haemorrhoid (prolapsed / thrombosed)
  • Rectal prolapse
  • Condyloma acuminatum (anal warts)
  • Skin tag
  • Tumour - squamous cell carcinoma, basal cell carcinoma, mucinous adenocarcinoma, Paget's disease
  • Perianal abscess


Haemorrhoids are cushions of anal vascular tissue that may bleed, prolapse, thrombose or cause pain / pruritis.
  • Look For

  • Perianal or rectal mass - flesh / mucosal appearance
  • Thrombosed mass - purple or blue, may be associated with overlying clot
  • Blood
  • Mucus discharge
  • Severity

  • First degree - non-prolapsed
  • Second degree - prolapse and reduce spontaneously
  • Third degree - reduce with manual pressure
  • Fourth degree - unable to be reduced
  • Risk Factors for Haemorrhoids

  • Straining while defaecating
  • Raised intra-abdominal pressure
  • Congenital
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