How common is diarrhoea in gastroenteritis?

Gastroenteritis irritates the stomach and intestines, commonly because of an infection. The bowel may move contents faster and draw extra water into the stool, producing loose or watery bowel movements. Abdominal cramping, nausea, vomiting, reduced appetite, and a mild fever can occur alongside diarrhoea. Symptoms may begin suddenly and improve as the irritation settles.

The presence of diarrhoea alone does not identify its cause. Food intolerance, medication effects, and other bowel problems can also lead to loose stools. The pattern, recent contacts, travel, food exposure, and associated symptoms help a clinician assess the likely explanation.

Take frequent small sips of water or an oral rehydration drink, especially after each loose stool or episode of vomiting. Eat when able; simple foods may feel easier while your stomach is unsettled. Rest, wash hands carefully with soap and water, and avoid preparing food for other people while you are unwell. Do not take diarrhoea-stopping medicine without checking that it is suitable, particularly if you have fever or blood in the stool.

Seek prompt medical advice if you cannot keep fluids down, pass very little urine, feel faint or confused, or develop signs of dehydration such as a very dry mouth. Contact a clinician for blood or black stool, severe or worsening abdominal pain, a high fever, or diarrhoea that is not settling. Babies, older adults, pregnant people, and anyone with a long-term illness may need advice earlier because fluid loss can become serious more quickly.

Ask whether your symptoms fit gastroenteritis, how to replace fluids, and which medicines should be avoided. Tell the clinician when the diarrhoea began, how often it is happening, whether vomiting or fever is present, and whether anyone else became ill after the same meal or exposure.