Haemorrhoids

Question 1

What are haemorrhoids?

Answer 1

They are vascular structures in the anal canal. In their normal state, they are cushions that help with stool control.

They become a disease when swollen or inflamed; the unqualified term “hemorrhoid” is often used to refer to the disease

Question 3

Where is the anal canal?

Where are the anal sphincters?

How do they work?

What are their roles?

Answer 3

• The anal canal runs from the superior aspect of the pelvic diaphragm to the anus, and is normally collapsed
• The internal sphincter is an involuntary sphichter surrounding the upper 2/3rd of the anal canal
  
  • Tonic contraction is stimulated by sympathetic fibres from the superior rectal/hypogastric plexus
  • Parasympathetic fibres inhibit this tonic contraction, thus requiring contraction of puborectalis/the external anal sphincter to maintain continence
• The external anal sphincter surrounds the lower 2/3rd of the anal canal, and is under voluntary control, mediated by the inferior rectal nerve (S4)
• Aside from sphincter function, they provide important sensory information, allowing differentiation between solid, liquid and gas

Question 4

How can you differentiate between internal and external haemorrhoids?

Answer 4

Internal haemorrhoids

• originate from above the dentate (pectinate) line, therefore are covered with columnar epithelium (endoderm), and are not painful.
• They drain via the superior rectal vein into the portal venous system.
• The cushions make up internal haemorrhoids.

External haemorrhoids

• originate from below the dentate line, therefore are lined with epithelium (ectoderm) and innervated by cutaneous branches of the pudendal nerve – and become painful
• They drain via the middle and inferior rectal veins into the systemic circulation
• External haemorrhoids may cause problems around the entire circumference of the anus.

Question 5

Describe the pathology of haemorrhoids?

Where are they? (anatomy)

Answer 5

• The anal cusions are highly vascular areas, formed of smooth muscle with subepithelial anastomoses of the rectal arteries/veins
• The anal cushions contribute to continence along with the anal sphincter, and are at 3, 7 and 11 o’clock when viewed from the lithotomy position
• Haemorrhoids (piles) are prolapses of these cushions, containing the normally dilated rectal venous plexus covered by rectal muscosa
• They are though to arise due to a breakdown of the smooth muscle layer, the muscularis mucosae

Question 8

What are the symptoms of haemorrhoids?

Answer 8

• Rectal bleeding (bright red on the paper)
• Prolapse
• Mucous discharge
• Pruritis ani
• Pain if the piles become thrombosed

Question 9

What are complications of haemorrhoids?

Answer 9

• Anaemia
  
  • If severe/continued bleeding
• Thrombosis
  
  • If prola[sing piles are gripped by the anal sphicter (‘stangulated piles’) then venous return is occluded, leading to thrombosis
  • The haemorrhoids swell, become purple and tense, causing significant pain/distress
  • the thrombosed piles often fibrose within 2-3 weeks, giving spontaneous cure

Question 10

What examinations would you do for a patient with haemorrhoids?

Why? What might you find?

Answer 10

• Abdominal examination
  
  • Palpable masses, enlarged liver
• Rectal examination
  
  • Prolapsing haemorrhoids are obvious
  • Inspection of the perineum may show large external haemorrhoids at 3, 7 and 11 (left lateral, right posterior, right anterior) and will disclude other DDxs, but anal cancer may look similar
• Proctoscopy/rigid sigmoidoscopy
  
  • Can visualize teh haemorrhoids/piles and assess for a lesion higher in the rectum
• Colonoscopy/Flexi-sigmoidoscopy
  
  • If symptoms suggest a more sinister pathology

Question 11

What are the differential diagnosis for rectal bleeding?

(not an objective but useful to know)

Answer 11

• Haemorrhoids (most common cause)
• Anal fissure (exquiste tenderness, skin tag)
• Diverticulitis (bloody ‘splash’ in the pan, LIF symptoms)
• Rectal cancer (tenesmus [cramping rectal pain/need to have a bowel movement], PR bleeding with defecation)
• Colon cancer (red blood mixed with the stool, change in bowel habit)
• Ulcerative colitis (abdominal pain, urgency to defecate)
• Crohn’s disease (weight loss, chronic diarrhoea)
• Massive upper GI bleed (usually melena, but frank blood if very large, usually haematemesis also)
• Trauma
• ischaemic/infective colitis
• Angiodysplasia