Metabolism
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Children with fatty diarrhoea
LD was referred to the Great Ormond Street Hospital for Sick Children when he was 2½ years old by his GP, who wrote
"He has always had very peculiar greasy stools. The greasy part of the stools is always yellow or orange in colour and tends to separate from the rest of the motion. It floats on water; solidifies like flakes on cold water or like drops of oil on hot water. It tends to seep through his clothes. His bowel habit is regular, one or two motions daily. His development is normal for his age."
His weight and height were also normal for his age.
(From Sheldon W, Arch Dis Childhood 39: 268 1964)
Normally,
about 2 hours after a moderately fat-rich meal a plasma sample is milky due
to the presence of chylomicrons, as shown in the sample on the right of the
picture. Chylomicrons are relatively large plasma lipoproteins - droplets of
triacylglycerol emulsified by surface proteins, unesterified cholesterol and
phospholipids. They have a diameter of 0.1 - 1 µm, which is large enough
to scatter light, hence the milky appearance of the plasma. Over a period of
2 - 3 hours the plasma becomes clear again, as chylomicrons are cleared from
the circulation, as shown in the sample on the left of the picture.
The graph below shows the formation and clearance of chylomicrons in LD and a control subject after a moderately high fat meal:
(From Sheldon W, Arch Dis Childhood 39: 268 1964)