A laboratory technique that measures the heat released by the combustion of a sample of feces, which can be used to determine the energy content of the feces and estimate the amount of energy that was not absorbed by the body. Bomb calorimetry can be used as a marker of malabsorption and gastrointestinal dysfunction, but there only little evidence in the field of critical care medicine: daily feces production of 250 g or a fecal weight > 350 g/day in ICU patients may be used a biomarker applicable in daily practice and can act as a surrogate for fecal energy loss and intestinal energy absorption.
References:
Wierdsma NJ, Peters JH, Weijs PJ, Keur MB, Girbes AR, van Bodegraven AA, Beishuizen A. Malabsorption and nutritional balance in the ICU: fecal weight as a biomarker: a prospective observational pilot study. Crit Care. 2011;15(6):R264. doi: 10.1186/cc10530. Epub 2011 Nov 9. PMID: 22071233; PMCID: PMC3388706.
Strack van Schijndel RJ, Wierdsma NJ, van Heijningen EM, Weijs PJ, de Groot SD, Girbes AR. Fecal energy losses in enterally fed intensive care patients: an explorative study using bomb calorimetry. Clin Nutr. 2006 Oct;25(5):758-64. doi: 10.1016/j.clnu.2005.11.012. Epub 2006 May 15. PMID: 16698144.