Patients with chronic renal failure have abnormal small intestinal motility and a high prevalence of small intestinal bacterial overgrowth

Background/Aims: Gastrointestinal (GI) symptoms are common among patients with chronic renal failure (CRF). The pathogenesis of these symptoms is probably multifactorial. Our aims were to assess gastric and small intestinal motility and the prevalence of small intestinal bacterial overgrowth (SIBO) in order to clarify possible pathophysiological mechanisms behind these symptoms in CRF patients. Methods: Twenty-two patients with CRF, 12 with GI symptoms and 10 without GI symptoms underwent antroduodenojejunal manometry. All patients with GI symptoms had diarrhea and half of them had abdominal pain, nausea and/or early satiety. Symptoms were unexplained by conventional investigations. Interdigestive motility was recorded for 5 h and postprandially for 1 h. Samples for culture from the small intestine were obtained through the manometry catheter. Results were compared with 34 healthy controls. Results: On manometry, 11 CRF patients demonstrated neuropathic-like abnormalities, with no significant difference between the patients with (7/12) and without (4/10) GI symptoms. SIBO was seen in 8 CRF patients (36%), 3 with and 5 without GI symptoms (p = 0.15). Six of eleven (55%) of the CRF patients with neuropathic-like abnormalities had SIBO, compared to 2/11 (18%) in those without abnormalities on conventional analysis (p = 0.07). The propagation velocity of phase III was significantly faster in CRF patients with GI symptoms compared to CRIF patients without symptoms and healthy controls (21.4 (16.4-54.7) vs. 8.1 (4.6-9.6) and 10.8 (7.2-21.6) cm/min, p = 0.007 and p = 0.019, respectively). We found a higher proportion of retrograde pressure waves in late phase II in the proximal duodenum in patients with and without GI symptoms, than in healthy controls (29 (1738) and 16 (14-42) vs. 8 (0-24)%, p < 0.0001 and p = 0.0005, respectively). The number of long clusters during the fasting recording was higher in both patient groups than in controls (9 (5-21) and 11 (7-15) vs. 4 (2-9)/5, p = 0.046 and p = 0.002, respectively). Conclusion: In the small intestine, abnormal motility and bacterial over-growth are common in patients with chronic renal failure. These alterations correlate poorly with GI symptoms, but disturbed intestinal motility might explain diarrhea in some of these patients. Copyright (C) 2003 S. Karger AG, Basel.