Abdominal distension occurs when substances, such as air (gas) or fluid, accumulate in the abdomen causing its outward expansion beyond the normal girth of the stomach and waist. It is typically a symptom of an underlying disease or dysfunction in the body, rather than an illness in its own right. People suffering from this condition often describe it as "feeling bloated." Sufferers often experience a sensation of fullness, abdominal pressure and possibly nausea, pain or cramping. In the most extreme cases, upward pressure on the diaphram and lungs can also cause shortness of breath. Through a variety of causes (see below), bloating is most commonly due to buildup of gas in the stomach, small intestine or colon. The pressure sensation is often relieved, or at least lessened, by burping (belching) or passing gas (flatulence). Medications that settle gas in the stomach and intestines are also commonly used to treat the discomfort and lessen the abdominal distension.
Waterborne diseases are caused by pathogenic microorganisms that most commonly are transmitted in contaminated fresh water. Infection commonly results during bathing, washing, drinking, in the preparation of food, or the consumption of food thus infected. Various forms of waterborne diarrheal disease probably are the most prominent examples, and affect mainly children in developing countries; according to the World Health Organization, such disease account for an estimated 4.1% of the total DALY global burden of disease, and cause about 1.8 million human deaths annually. The World Health Organization estimates that 88% of that burden is attributable to unsafe water supply, sanitation and hygiene.