Effect of human bowel wall distension on translocation of indigenous bacteria and endotoxins

The effect of colonic distension on the translocation of indigenous bacteria and endotoxins was prospectively assessed in 50 consecutive patients undergoing colonoscopy. Semiquantitative bacteriologic cultures, chromogenic LAL testing for endotoxemia, and serial determinations of inflammatory markers were used. At the end of the endoscopic procedure, true bacteremia was found in only two patients with obstructing colorectal cancer. There was no evidence of systemic endotoxemia either being induced or increased during the observation period. The endotoxin detoxifying plasma capacity was elevated in patients with preexisting inflammation and did not change within this period. Levels of TNF-alpha, interleukin-6 (IL-6), and elastase (E alpha 1PI) did not differ from baseline values. C3 alpha levels increased in 20% of the patients, whereas fibrinopeptide A values rose by up to 10(2) during colonoscopy. However, since neither endotoxin, TNF alpha, nor IL-6 levels were found to be elevated in this study, the excessive activation of the coagulation system must be related to the distension of bowel wall vessels rather than to an effect of endotoxins escaping from the lumen.