Fermentation in ileostomy bags: Control of excessive gas with diet, pH and antibiotics

The composition of early morning gas from the bags of 10 ileostomates was determined using gas chromatography. Seven of the 10 had a predominance of gases attributable to bacterial fermentation (H₂ and CO₂, 70 ± 12%). The remaining three contained mainly atmospheric gases, N₂ and O₂, with only small amounts of fermentation gases (7 ± 3%).
When a controlled low fibre (0.7 g) dinner was substituted for a high fibre (13.5 g) evening meal, there was a corresponding decrease in the volume of fermentation gas in the ileostomy bag the next morning ( P < 0.05).
Gas production from ileostomy effluent was inhibited in vitro by 10 < pH < 5 and by antimicrobial agents. The most effective were metronidazole, chloramphenicol, tetracycline, erythromycin and chlorhexidine. These reduced fermentation gas by more than 95%.
It was concluded that the majority of the gas produced by ileostomates is formed by bacterial fermentation of the faecal waste in their ileostomy bag and that this may be controlled by careful manipulation of their diet.