Infections
Norovirus, known as the ‘winter vomiting bug’, is responsible for 20% of infectious diarrhoea cases. The viral infection causes vomiting and diarrhoea, typically lasting two to three days. It's most commonly caught during winter in the UK, but you can catch it throughout the year. Most cases resolve on their own and don’t require any treatment.
A stomach bug is the inflammation of the gastrointestinal tract (which includes the stomach, intestine, and liver) leading to diarrhoea, vomiting, and abdominal pain. It can be caused by bacteria, like E.coli, or viruses. It’s most common in children, often transmitted by ingesting contaminated foods or coming into contact with an infected person. There’s no specific treatment for it if the cause is viral; it’s best to let your stomach settle down by avoiding solid foods for a few hours, eating bland food and drinking plenty of water.
Traveller diarrhoea (TD) is diarrhoea experienced while in a foreign country. It’s usually accompanied by symptoms like nausea, vomiting, abdominal cramps, and fever. It affects around 10% to 40% of travellers, especially those who travel from developed to developing regions. While TD can resolve on its own, dealing with diarrhoea in another country can be uncomfortable. So it's good to bring loperamide (an anti-diarrhoea tablet) with you for emergencies. Depending on the country you're visiting, you might be prescribed a short-term course of antibiotics as well as a backup in case you develop diarrhoea.
Food poisoning also falls into this category. It occurs when you eat foods contaminated with viruses, bacteria or parasites. Symptoms can include nausea, diarrhoea, vomiting, fever and feeling unwell. It usually resolves on its own but can take a few days.
Food intolerances
Certain food sensitivity can lead to diarrhoea. Common culprits include milk, coffee and spicy foods. Food-related diarrhoea often resolves on its own without intervention.
Lactose intolerance is a condition where a person has trouble digesting lactose (the sugar in milk) due to low quantities of lactase, the enzyme responsible for breaking down lactose. People with lactose-intolerance who consume dairy products can experience diarrhoea as quickly as 30 minutes. The symptoms can last anywhere from hours to days, depending on how much dairy is consumed. Lactase supplements can prevent these symptoms from occurring.
Underlying conditions
Conditions like irritable bowel syndrome (IBS) and IBD can cause inflammation in the bowel, resulting in diarrhoea.
IBS symptoms can include abnormal bowel habits, abdominal cramps, diarrhoea, constipation or both. There’s no treatment for IBS, but you might be able to control flare-ups with antispasmodic tablets and following the FODMAP diet. You can also treat IBS-related diarrhoea with loperamide.
IBD is an umbrella term for chronic bowel conditions, such as Crohn's disease and ulcerative colitis, which cause intense stomach pain and diarrhoea. A telltale sign of ulcerative colitis is bloody diarrhoea with or without mucus. If you notice persistent bleeding in your stool, seek medical attention immediately. There are treatments for IBD, including aminosalicylates, corticosteroids and anti-TNF agents, which all help control inflammation. IBD can get worse over time and lead to serious complications, so it’s important to consult with your doctor to find the right treatment.
