Sleeve gastrectomy (SG) is a bariatric procedure resulting in long-term weight loss, but detailed studies on gastric contractility and gastrointestinal transit in the same subject are absent. This study aimed to evaluate the effects of SG on gastrointestinal motility in rats using alternating current biosusceptometry (ACB).

Male Wistar rats were fed with a high sugar-fat diet for 12 weeks and randomly assigned to four experimental groups: Control; Control + SG; Obese; and Obese + SG. GI motility measurements were performed using the ACB technique. Mean gastric emptying time (MGET), mean cecum arrival time (MCAT), and frequency gastric contractility were assessed. Moreover, nutritional, lipid profile, and morphometry analysis, were evaluated 30 days after surgery. Data were analyzed by ANOVA followed by post Tukey or Kruskal-Wallis test followed by Dunn's multiple comparisons test.

SG significantly accelerated both MGET and MCAT compared to controls, indicating faster gastric emptying and orocecal transit. Gastric contractility was severely impaired, with reduced dominant frequency and non-stationary, non-sinusoidal waveforms observed post-SG. Morphometric analysis revealed reduced mucosal and muscularis layer thickness and increased leukocyte infiltration, indicating inflammation and tissue remodeling.

The excision of the gastric greater curvature in SG induced persistent dysmotility, accelerating GI transit and impairing gastric contractile function, accompanied by significant morphometric changes. These alterations may have long-term effects, underscoring the importance of extended follow-up in SG studies.