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1. What are the causes of bright red rectal bleeding?
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Correct answer:
The passage of bright red blood per rectum is a common symptom, which the patient usually attributes to ‘piles’; indeed, haemorrhoids are by far the commonest cause of rectal bleeding. It is important, however, to bear in mind a list of possible causes of this symptom.
(1) General causes: bleeding disorders (rare).
(2) Local causes: tumours of the colon and rectum (benign or malignant); haemorrhoids; diverticular disease; ulcerative colitis; fissure in ano; haemorrhage (rarely); angiodysplasia of the colon; trauma.
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2. Can a bleeding duodenal ulcer cause bright red rectal bleeding?
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Correct answer:
Rarely, massive haemorrhage from higher up the alimentary canal - even a bleeding duodenal ulcer - may produce bright red blood per rectum instead of the usual melaena, although such cases are commonly accompanied by haematemesis.
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3. What is the functional anatomy of haemorrhoids?
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Continence is partly a function of the anal sphincters, and partly a consequence of the anal cushions. The anal cushions comprise highly vascular tissue lining the anal canal, with a rich blood supply from the rectal arteries, which anastomose with the draining veins both through capillaries and through direct arteriovenous shunts. The draining veins form saccules, commonly just below the dentate line, which then drain via the superior rectal vein. The venous saccules are supported by smooth muscle to form the cushions. Apposition of these subepithelial vascular cushions is important for continence of gas and fluid.
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4. What are the two important structures involved in anal continence?
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Correct answer:
Anal sphincters and anal cushions.
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5. What makes up an anal cushion?
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Correct answer:
The anal cushions comprise highly vascular tissue lining the anal canal, with a rich supply from the rectal arteries, which anastomose with the draining veins both through capillaries and through direct arteriovenous shunts. The draining veins form saccules, commonly just below the dentate line, which then drain via the superior rectal vein. The venous saccules are supported by smooth muscle to form the cushions.
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6. Which arteries give blood supply to the anal cushions?
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Correct answer:
The rectal arteries.
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7. Which veins drain the anal cushions?
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Correct answer:
The superior rectal vein.
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8. Where are the draining veins of the anal cushions commonly felt?
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Correct answer:
Just below the dentate line.
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9. How are haemorrhoids classified?
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Correct answer:
Haemorrhoids (or piles; the words are synonymous) may be classified according to their relationship to the anal orifice into internal, external and interoexternal.
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10. What is an internal haemorrhoid?
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Correct answer:
An internal haemorrhoid is a congested vascular cushion with dilated venous compartments draining into the superior rectal veins.
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11. What is the external haemorrhoid?
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Correct answer:
External haemorrhoids is a term that should be abandoned, as it is applied to a conglomeration of quite different entities including perianal haematoma (‘thrombosed external pile’), the ‘sentinel pile’ of fissure in ano and perianal skin tags. Strictly speaking, internal piles that prolapse should be termed interoexternal haemorrhoids, but this term is seldom employed.
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12. What is the pathology of haemorrhoids?
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Correct answer:
Internal haemorrhoids, or piles, are abnormal anal cushions, usually congested as a result of straining at stool, and traumatized by the passage of a hard stool. The anal cushions are particularly prominent in pregnancy owing to the venous congestion caused by the large gravid uterus and the laxity of the supporting tissues caused by the influence of progesterone. With the patient in the lithotomy position the usual arrangement is that three major piles occur at 3, 7 and 11 o’clock.
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13. When are internal haemorrhoids more common?
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Correct answer:
During pregnancy owing to venous congestion caused by the large gravid uterus and the laxity of the supporting tissues caused by the influence of progesterone.
