Water accounts for roughly 60 to 70 percent your body weight. Your system requires a steady supply of fresh water to replenish losses in your urine, stool and sweat. Although your body can process and eliminate several gallons of water each day, quickly consuming a large amount of water can temporarily stretch and bloat your stomach.
Your stomach is a muscular, J-shaped pouch that sits in the upper portion of your abdomen on the left side. Like a balloon, your stomach expands as it fills with food and liquid. When empty, your stomach capacity is roughly a quarter cup. In the empty state, your stomach resides primarily behind your lower left ribs. When you eat or drink, your stomach can stretch to accommodate roughly 6 cups. As your stomach fills, it expands forward, downward and sideways toward the center of your abdomen. If your intestines are full, your stomach may expand upward toward your lungs.
Water Consumption and Bloating
Several factors influence whether drinking water leads to temporary stomach bloating, including the volume of water you consume and how quickly; what else is in your stomach; and whether your intestines are also full. On an empty stomach, one or two 8-ounce glasses of water are unlikely to cause noticeable bloating. In contrast, a quart or more of water consumed quickly with other food or liquid already in your stomach, may lead to some distension of your abdomen. Similarly, if your intestines are full due to a recent meal, constipation or both, quickly consuming a quart or more of water may cause temporary stomach bloating and discomfort. The larger the volume of water and other foods or liquids in your stomach, the more likely you will experience temporary bloating.
Medical conditions and other factors that slow stomach emptying may increase the likelihood of experiencing temporary bloating when you drink a lot of water. Narcotic pain killers, acid reflux disease, the stomach flu, bulimia, anorexia nervosa, an underactive thyroid gland, Parkinson's disease and nerve damage associated with diabetes, each commonly delay stomach emptying. Drinking water slowly helps prevent stomach bloating if you have one or more of these conditions.
Although rare, consumption of an extremely large volume of water in a short period may lead to water intoxication. With this condition, your stomach becomes painfully bloated from overfilling. The severe stomach distension often leads to vomiting. When excess water floods your bloodstream more quickly than your kidneys can excrete it, your organs and tissues swell. In severe cases, water intoxication may lead to death.