Magnesium faeces

Keywords: Faeces Mg, Magnesium faeces

Specimen:

24 h faecal collection.

Method:

Atomic absorption spectrophotometry, spectrophotometry.

Reference Interval:

< 45 mmol/L; < 15 mmol/24 h

Application:

Identification of magnesium-containing laxatives as the cause of diarrhoea.

Documentation of increased loss of magnesium from the gut as a cause of Hypomagnesaemia.

Interpretation:

Patients with diarrhoea due to surreptitious self-administration of magnesium-containing laxatives show increased faecal magnesium, as do patients with Hypomagnesaemia due to magnesium loss from the gut.

Reference:

Fine KD et al. N Engl J Med. 1991; 324: 1012-1017.