Altered motility and duration of bacterial overgrowth in experimental blind loop syndrome

To better understand the pathogenesis of the increased motility previously described in the blind loop rat, we studied the relationship between duration of bacterial overgrowth and both myoelectric activity and bacterial flora in this model. Myoelectric studies and quantitative bacterial cultures were performed on self-filling and self-emptying (control) blind loop rats, one, two, and three weeks postoperatively. All self-filling blind loop rats had greater random action potential activity and higher frequencies of migrating action potential complexes than controls (P<0.05). One-week self-filling blind loop rats had a higher frequency of migrating action potential complexes (P<0.05) and a higher ratio of counts of Escherichia coli to Bacteroides species (P<0.05) than the two- or three-week self-filling blind loop groups. Thus, qualitative changes in myoelectric activity occur during the development of bacterial overgrowth in the blind loop rat which may reflect evolving alterations in the bacterial flora.