Low Ileocecal Valve Pressure Is Significantly Associated with Small Intestinal Bacterial Overgrowth (SIBO)

Small intestinal bacterial overgrowth (SIBO) is a significant and increasingly recognized syndrome. While the development may be multifactorial, impairment of the ileocecal valve (ICV), small bowel motility, and gastric acid secretion have been hypothesized to be risk factors. ICV dysfunction remains largely unexplored using standard technology. The wireless motility capsule (WMC) that evaluates pressure, pH, and temperature throughout the GI tract provides the ability to assess these parameters. The primary aims of this study were to assess the relationship of ICV pressures, small bowel transit time (SBTT) and intestinal pH with lactulose hydrogen breath testing (LBT) results in subjects with suspected SIBO. We retrospectively studied consecutive patients referred to our institution for WMC and LBT from 2010-2012. Ileocecal junction pressures (IJP), as a surrogate for ICV pressures, were defined as the highest pressure over a 4-min window prior to the characteristic ileocecal pH drop. SBTT and pH were calculated and compared with LBT results. Twenty-three patients underwent both WMC and LBT, with positive results observed in 15 (65.2 %). IJP were significantly higher in LBT(-) negative vs. LBT(+) (79.9 vs. 45.1, p < 0.01). SBTT was significantly longer in LBT(+) versus LBT(-) (5.82 vs. 3.81 h, p = 0.05). Among LBT(+) subjects, gastric pH was significantly higher versus LBT(-) subjects (2.76 vs. 1.63, p = 0.01). There was poor correlation between IJP and other parameters (SBTT, small bowel pH, and gastric pH). Low IJP is significantly associated with SIBO. While this is physiologically plausible, to our knowledge, this is the first study to make this connection. Prolonged SBTT and higher pH are also independently associated with SIBO. Our findings add value of the WMC test as a diagnostic tool in patients with functional gastrointestinal complaints and suggest re-focus of attention on the ileocecal valve as a prominent player in intestinal disorders.