What causes vomiting of yellow fluid on an empty stomach?

Under normal physiological conditions, bile does not enter the stomach. It is secreted by the liver and discharged into the descending duodenum via the ampulla of Vater—the opening of the common bile duct—then proceeds into the distal intestine. If bile enters the oral cavity, bile reflux should be suspected. So, what causes yellowish fluid vomiting on an empty stomach? The following explains this issue.

Causes of Yellowish Fluid Vomiting on an Empty Stomach

1. Dietary Factors

Consuming a large meal or excessive alcohol the previous evening—especially without adequate physical activity before sleeping—may lead to bile and gastric acid reflux upon waking the next morning, resulting in vomiting of bitter-tasting yellowish fluid. Therefore, it is advisable to maintain a light, bland diet and avoid spicy or irritating foods. Additionally, yellowish fluid vomiting may also occur during early pregnancy.

2. Acute Enteritis

Acute gastroenteritis is commonly caused by viral or bacterial infection. It typically develops after ingestion of spoiled food contaminated with viruses or bacteria, leading to acute gastric inflammation. A complete blood count (CBC) may reveal elevated white blood cell and neutrophil counts, indicating bacterial acute gastritis. Treatment under medical supervision—including appropriate antimicrobial or symptomatic medications—is recommended. Moreover, chronic pharyngitis may, in the fasting state, irritate the mucosa and trigger yellowish fluid vomiting.

3. Bile Reflux

Bile reflux can arise from either organic or functional causes. Organic causes include cholecystectomy and biliary calculi—conditions often associated with impaired bile secretion. Functional causes involve abnormal motility of the antrum, pyloric sphincter, and duodenum. Accordingly, patients are advised—under physician guidance—to take medications that regulate bile secretion and enhance gastric motility to alleviate symptoms.

The above outlines potential causes of yellowish fluid vomiting on an empty stomach. We hope this information is helpful to you.