Effects of Chronic Renal Failure on Gastrointestinal Motility: A Study on the Changes of Gastric Emptying, Small Intestinal Transit, Interdigestive Myoelectric Complex, and Fecal Water Content

Background: Gastrointestinal (GI) dysfunction may lead to malnutrition in patients with chronic renal failure (CRF). This study investigated the effects of CRF on GI motility. Methods: Forty-eight Sprague Dawley rats (180 +/-+/- 20 g) were randomly classified into CRF group and sham-operated (Sham) group, and each group was further assigned for gastric emptying (GE), small intestinal transit (SIT), interdigestive myoelectric complex (IMC), and fecal water content (FWC) experiments (6 CRF and 6 Sham rats per experiment). The CRF model was established by 5/6 nephrectomy. The body weight (BT), GE, SIT, IMC, and FWC of the rats were observed. ANOVA and Student--Newman--Keuls q-test were utilized to do statistical analysis. Results: The BT of the rats in the two groups had no statistical difference before surgery. But in the ninth week after surgery, the CRF rats (230 +/-+/- 20 g) weighed less than the Sham rats (260 +/-+/- 15 g) (p < 0.05). The GE rate and SIT rate in CRF rats were significantly lower than that of Sham rats (GE 33.08 +/-+/- 7.50 vs. 53.37 +/-+/- 9.78%%; SIT 42.92 +/-+/- 8.96 vs. 58.67 +/-+/- 9.12%%) (p < 0.05). Compared with the IMC of the Sham rats, the CRF rats showed obvious alterations in (a) IMC cycle; (b) phase II and phase III duration; and (c) phase III cycling frequency, amplitude, and percentage (p < 0.05). FWC of the CRF rats increased significantly (p < 0.05). Conclusion: The GI motility of the CRF rats is obviously impaired. This finding may indicate that the effects of CRF on GI motility might be relatively prevalent.</.