Contaminated food or water, contact with a person who has the virus, or poor hygiene practices that spread bacteria and viral infections are causes of a stomach bug, also called gastroenteritis, explains WebMD. Common symptoms include vomiting, diarrhea, stomach pain, nausea, fever and headache.
People who have contracted a stomach bug may also become dehydrated when vomiting and experiencing diarrhea, according to WebMD. Signs of dehydration include a dry mouth, lightheadedness, a thirsty feeling and dry skin.
Additional causes of gastroenteritis include toxins found in certain types of seafood; consumption of acidic foods, such as tomatoes and citrus fruit; and drinking water with heavy metals present, such as cadmium, lead, mercury or arsenic, according to WebMD. Some medications, such as chemotherapy drugs, antibiotics, antacids and laxatives, sometimes produce symptoms of gastroenteritis.
Physicians typically recommend drinking plenty of fluids when suffering from a stomach bug, explains WebMD. Fluids help keep the body hydrated so that the immune system can fight off the viral infection. Antibiotics and over-the-counter medications are not usually effective in treating gastroenteritis, so physicians recommend rest, fluids and a slow introduction of soft foods to ease the nausea, vomiting and diarrhea. If symptoms persist for more than a week, the individual should consult with a medical professional.