Gastroenteritis

Overview

Gastroenteritis is an infection of the stomach and intestines. It is also called a stomach bug or stomach flu. It commonly causes diarrhea, vomiting, and tummy cramps. Your body usually clears the infection on its own within a few days.

Yes, gastroenteritis is extremely common. Most people will get it at least once in their life. It spreads quickly among families, schools, nurseries, and care homes.

Anyone can get gastroenteritis. It is usually harmless, but it can be more serious in babies, young children, older adults, and people with weakened immune systems.

Symptoms

Common symptoms

• Watery diarrhea
• Vomiting or feeling sick
• Stomach cramps or tummy pain
• A mild headache
• A low-grade fever
• Feeling tired and achy

Symptoms in children

• Runny diarrhea and being sick
• A high temperature
• Stomach cramps
• Being cranky or crying more than usual
• Being less active than normal
• Refusing to drink or eat

Symptoms in older adults

• Diarrhea and vomiting
• Feeling dizzy or lightheaded
• Muscle weakness
• Confusion or unusual drowsiness
• Passing very little urine
• Dry mouth or feeling very thirsty

Causes

Main causes

• Viruses, such as norovirus and rotavirus
• Bacteria, such as Salmonella, Campylobacter, or E. coli
• Parasites like Giardia, often found in contaminated water
• Food poisoning from eating food or water that has bacteria or their toxins
• Spreading from person to person through touching surfaces or sharing utensils

Risk factors

• Living or working in close contact with someone who has gastroenteritis
• Traveling to areas with unsafe drinking water or poor sanitation
• Eating in places where food is not prepared hygienically
• Being a young child, an older adult, or having a weak immune system
• Taking medicines that reduce stomach acid or weaken the immune system

When to see a doctor

See a doctor urgently if:

• You or your child cannot hold down any fluids for a whole day
• You see blood in your vomit or bowel movements
• You have a severe pain in your tummy that does not get better
• You feel very dizzy, confused, or have fainted
• You have not passed urine for 12 hours (or a child for 6-8 hours)
• Your child is unusually sleepy, irritable, or has sunken eyes

Book a routine appointment if:

• Your symptoms do not improve after a week
• You are worried about dehydration and need advice on rehydration
• You are caring for someone with gastroenteritis and they seem to be getting worse
• You have a long-term health condition and want to know if you need extra care

Diagnosis

Usually, your doctor can tell if you have gastroenteritis by listening to your symptoms and giving you a simple check-up. They may ask about your recent food, travel, and contact with others who are ill. In most cases, no tests are needed.

Tests that may be done

• A stool (poo) sample, if your doctor suspects bacteria or parasites
• A blood test, if they are worried about dehydration or another issue
• A urine test, to see how concentrated your urine is (a sign of dehydration)

What to expect at your appointment

Your doctor will ask questions about your symptoms and medical history. They might press gently on your tummy to check for pain. They will explain what you can do at home and what signs to watch for. If tests are done, they will tell you when to call for results.

Treatment

There is no cure for gastroenteritis. It is an infection that your immune system fights off on its own. The most important treatment is preventing dehydration by drinking enough fluids. For most people, this means staying home and resting.

Self-care at home

• Drink plenty of clear fluids. Water, clear soups, and rehydration drinks from the pharmacy (they replace water and salts) are good choices.
• Sip small amounts often, rather than drinking a lot at once.
• Rest and stay home. Keep a bucket or toilet close by.
• If you feel like eating, start with bland foods like toast, rice, bananas, or plain crackers.
• Ask your pharmacist or doctor about safe over-the-counter medicines to control fever or pain. Do not take anything without checking first.

Medical treatments

In some cases, your doctor may suggest a rehydration solution to drink. If you are severely dehydrated, you may need fluids through a drip in a hospital. If tests show a bacterial or parasitic infection, your doctor might prescribe antibiotics or other specific treatment. Antibiotics will not help if the cause is a virus, so they are not given for typical viral gastroenteritis.

When is surgery considered?

Surgery is not used for gastroenteritis.

Living with this condition

While you are unwell, try to rest as much as you can. Make it easy to get to the toilet or keep a clean bucket nearby. Use your own towel and wash your hands often so you do not pass the infection to anyone else. You can usually return to work or school 48 hours after your last episode of diarrhea or vomiting.

Lifestyle tips

• Wash your hands well with soap and water after using the toilet, before eating, and before handling food.
• Stay off work, school, or nursery until the infection has gone.
• Avoid preparing food for other people for 48 hours after symptoms stop.
• If you are caring for someone who is ill, wash your hands after every contact.

Diet and exercise

Focus on fluids while you are unwell. When you are ready to eat, choose plain, starchy foods like dry toast, rice, mashed potatoes, or simple crackers. Avoid dairy, fatty, spicy, or very sugary foods for a few days. Once you are feeling better, a short walk can help you regain your energy.

Mental health and emotional wellbeing

Being ill with vomiting and diarrhea can be upsetting and stressful, especially if you are caring for a child or worried about being far from a toilet. It is normal to feel frustrated or anxious. If you feel low or overwhelmed, talk to your doctor or a trusted health professional. They can help you find support.

Prevention

Good hygiene is your best defence. Wash your hands often with soap and water, especially after using the toilet, changing nappies, before eating, and before cooking. Make sure food is cooked properly and kept refrigerated. When travelling to places with unsafe water, drink bottled or boiled water.

Vaccines

In many countries, there is a rotavirus vaccine that protects babies against one of the most common causes of severe gastroenteritis. Ask your health visitor or doctor if your child is eligible.

Complications

If left untreated

• Dehydration, which can be mild or severe and needs extra fluids
• An electrolyte imbalance, meaning your body loses important salts it needs to work properly
• In severe cases, dehydration can affect your kidneys and other organs
• Rarely, a bacterial infection can spread to other parts of the body

Long-term outlook

The outlook is very good. Most people recover fully within a few days to a week with fluids and rest. Even people who need hospital care for dehydration usually get better completely. Following your doctor's advice and keeping up with fluids will help you heal safely.

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