The pathogenesis of celiac disease is associated with an autoimmune process. The disease causes chronic inflammation of the small intestinal mucosa, which may affect the brain-gut axis. The activation of visceral receptors (gastrointestinal mechanoreceptor and osmoreceptor) in response to stomach distension caused by water ingestion has not been studied before. Our results showed reduced responsiveness of the autonomic nervous system to water ingestion in patients with celiac disease, which may lead to disturbances of gastric myoelectrical activity and depends on baseline autonomic activity. Water intake can induce gastric distension and motility response, without changes in gastrointestinal hormones. It can also increase the activity of the autonomic nervous system. On the other hand, inflammation in celiac disease (CeD) can alter visceral perception (increase sensitization), leading to autonomic dysfunction. We aimed to investigate the effect of water ingestion on autonomic activity measured as heart rate variability (HRV) and gastric myoelectrical activity measured by electrogastrography (EGG) in patients with CeD. The study included 53 patients with CeD and 50 healthy controls: mean (SD) age, 43.4 (14.8) years and 44.1 (9.2) years, respectively. Electrocardiography with HRV analysis and simultaneous 4-channel EGG was performed before and after the water load test (WLT) ingestion 500-ml water over 5 minutes. We found that compared with controls, at fasting, patients with CeD showed a reduced percentage of normogastria (P=0.045) and an average percentage of slow wave coupling (P<0.01) with increased dominant power (DP) (P<0.001). Moreover, water ingestion in CeD patients reduced the percentage of gastric arrhythmia (P<0.01) and increased the percentage of normogastria (P<0.01) and DP (P<0.01). Finally, in the CeD group, water ingestion increased HRV indices: low frequency by 116.9% (P<0.001), high frequency by 125.3% (P<0.01), but they did not reach the values of the control group. Patients with CeD showed a smaller increase in parasympathetic autonomic activity after the WLT than controls. Altered autonomic responsiveness may contribute to the disturbances of gastric myoelectrical activity and depends on baseline autonomic activity.