First Line Investigations

Flatus - Air Redistribution Test

The FART Test, which gives an analysis of flatus volume and methane content, was expected to be widely adopted given its convenience as a non-invasive technique, suitable for outpatient use.  However, it is no longer recommended as best practice owing to a number of disadvantages, outlined here:

  1. Inaccuracy in volume estimations.  Variations of up to 200% have been recorded in 24-hour flatus volumes, which cannot be fully corrected by adjustment for altitude/atmospheric pressure; even the most reliable collection devices have been shown to leak on occasion.
  2. Patient acceptability.  The technique is universally unpopular with patients.
  3. Safety concerns.  Although there are no reports of serious harm to date, the procedure undoubtedly represents a potential fire hazard, particularly in smokers or those on home oxygen.
  4. Difficulty in interpretation.  Although methane is a potent greenhouse gas (having approximately 25x the global warming potential of carbon dioxide [2]), measuring direct emissions may not give an accurate guide to an individual’s overall climate impact.  Indeed, low flatus volumes may well indicate a predominantly meat- and dairy-based diet, in which case methane emissions in the food chain would dwarf the relatively modest contributions from your patient’s intestinal tract  [1],[3].  Mathematical formulae could be made available to assist, but many clinicians do not feel confident in their use.