Acute gastroenteritis is a condition where an individual has acute onset of diarrhea and vomiting. This is a distressful situation and can become life threatening if not treated promptly. This mostly occurs due to infections. It can also be caused due to toxins released by bacteria, or as adverse reaction to a drug or allergy to some substance. The onset and severity varies depending on the underlying cause, amount of infection and resistance and general state of the affected person. The most common source of infection is ingestion of contaminated food or water. Lack of hygiene during cooking, serving or eating food is responsible for causing acute gastroenteritis. People swimming in rivers are at greater risk of acquiring infection and developing acute gastroenteritis, particularly after rains because the river water gets contaminated by the runoff contaminated water from the bank. Apart from this, people travelling from non endemic areas to areas of high prevalence of these infections are more susceptible to these infections as their body does not have enough antibodies against the causative germs. The infecting agent causes acute inflammation of the stomach and intestines resulting in acute diarrhea and vomiting. Viruses are the main source of infection for causing gastroenteritis in developed countries. Norovirus, rotavirus, adenovirus are some of the common sources of infection causing acute gastroenteritis. Different species of bacteria can cause acute gastroenteritis. Salmonella, Shigella, Clostridium, e.t.c., are the common bacteria causing acute gastroenteritis. Gastroenteritis can also be caused by helminthic infections like ascaris, pin worm, e.t.c. or protozoa infections like amoeba. Sometimes malaria can present with symptoms like acute gastroenteritis. Along with acute onset of diarrhea and vomiting, there may be abdominal pain with cramps. Mostly the diarrhea consists of blood mixed stool. But sometimes with protozoal infections one may have blood mixed stools which is very frightening for the person. Some patients present with high fever, more so if the infection is bacterial like salmonellosis, or shigellosis. Acute gastroenteritis can be easily prevented by maintaining good hygiene. One should keep the hands very clean while cooking, serving or eating food. Food handlers should keep their nails clipped short, otherwise germs can settle below the nails. The vegetables and meat to be cooked need to be washed very well before being cooked. The surface used to cut vegetables or any food item also should be maintained very clean to prevent any contamination. While eating out, it is important to select restaurants where food is prepared hygienically. If the hygiene of food is not ensured, it is preferable to eat fresh and hot food served immediately. Heat kills the infective germs thus reducing the chances of acquiring infections. Meat and meat products if not prepared hygienically carry greater risk of causing gastroenteritis. Hence it is advisable to consume meat and meat products only if one is sure that they are fresh and hygienically prepared. While drinking water, if one does not know whether it is clean or not, it is better to take hot tea or coffee instead, because hot beverages are usually germ free. Germs are destroyed due to the heat. The infecting agent causing acute gastroenteritis can be identified by doing microscopic examination of the stool sample or its culture growing the microbe. Acute gastroenteritis is usually self subsiding and does not require anti-infective agents routinely. But it is important to replenish the fluids and electrolytes lost from the body. This can be done by means of oral rehydration solutions or intravenous perfusions, depending on patient’s condition and accessibility of health care. Till the patient reaches a proper health care center, he can be given some home made rehydration solutions. Bananas help in stopping diarrhea and also replenish lost electrolytes. By maintaining very good hygiene, acute gastroenteritis can be prevented. But if somebody starts developing diarrhea and or vomiting it should be treated at the earliest. Dr. Rachna Pande is a specialist in internal medicine at Ruhengeri Hospital