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:
- 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.
- Patient acceptability. The technique is universally unpopular with patients.
- 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.
- 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.