INTERDIGESTIVE AND POSTPRANDIAL MOTILITY IN SMALL-INTESTINAL BACTERIAL OVERGROWTH

Background: Motility disorders are believed to be of major pathogeneti c importance in small-intestinal bacterial overgrowth (SIBO). The aim of this study was to investigate interdigestive and postprandial motil ity in a group of patients with SIBO and to compare the results with t hose of healthy volunteers. Methods: Twenty healthy subjects and 14 pa tients with SIBO were included. Exclusion criteria were obvious predis posing conditions. Antroduodenojejunal pressure recording was performe d after an overnight fast. After a 5-h interdigestive recording a stan dard meal was given, and postprandial recording performed for 30 min. Results: Significantly fewer patients than healthy subjects had phase- III activity in the antrum (3 of 14 versus 15 of 20; P < 0.01), and mo re patients lacked phase III completely (5 of 14 versus 0 of 20; P < 0 .05). Propagated single contractions in the proximal duodenum during l ate phase II and postprandially were also significantly reduced (1 (0- 5) versus 8 (5-12) per 30 min (median; interquartile range (IQR)) (P < 0.01) and 0.5 (IQR, 0-6.5) versus 8 (IQR, 6-13) per 30 min (P < 0.01) , respectively). In the distal part of the duodenum the patients had s ignificantly prolonged duration of phase III (7.8; IQR, 5.6-9.2 versus 5.9; IQR, 4.26-6.6 min) (P < 0.05) and increased motility index of ph ase III (6685; IQR, 4870-9999 versus 3605; IQR, 2579-5544 mm Hg x min/ 30 min) (P < 0.05), late phase II (10,285; IQR, 6105-11,384 versus 665 0; IQR, 4639-9102) (P < 0.05), and postprandially (12,960; IQR, 8454-1 8,644 versus 7917; IQR, 6132-10,551) (P < 0.05). Retrograde contractio ns predominated in the late part of phase III in the proximal duodenum in both groups. The cycle length of the MMC and the number of cluster ed contractions showed no difference between the two groups. Conclusio ns: A significant proportion of patients with SIBO, compared with heal thy subjects, lack interdigestive phase III activity, not only in the small intestine but also in the gastric antrum. They also have fewer p ropagated contractions in the proximal duodenum during interdigestive phase II. On the other hand, the motility index in the distal part of the duodenum was higher in patients with SIBO during phase III, late p hase II, and postprandially. The results are compatible with a reduced clearing function in the stomach and proximal duodenum and/or a compe nsatory increase of motility in the region of the duodenojejunal flexu re.