Gastroenteritis: Symptoms, Signs, and Treatment

Gastroenteritis is a common illness that affects people of all ages, with young children being especially vulnerable. It occurs when the stomach and intestinal lining become inflamed, often due to a viral, bacterial, or parasitic infection. Gastroenteritis shows symptoms like vomiting and diarrhea.

What is Gastroenteritis?

An infection or inflammation of the digestive system can cause gastroenteritis. Symptoms such as vomiting, diarrhea, and cramping in the abdomen are common. The illness often gets better on its own in a matter of days. Gastroenteritis can be caused by a number of things, including bacteria, viruses, bacterial toxins, parasites, specific chemicals, and some medications. Gastroenteritis is highly transmissible.

Types of Gastroenteritis

• Viral gastroenteritis – The most prevalent kind of gastroenteritis is stomach flu, caused by viral infections. In 60% of cases, viruses are the cause of gastroenteritis. 50% of cases of viral gastroenteritis are caused by norovirus alone.
• Bacterial gastroenteritis – Bacterial gastroenteritis is brought on by bacterial infections. 
• Fungal gastroenteritis – Fungal gastroenteritis can be brought on by fungal infections.
• Chemical gastroenteritis – The lining of your stomach and intestines can become damaged and inflamed by chemicals. Even in tiny quantities, certain chemicals have this effect. Others, such as alcohol and some drugs, can result in gastroenteritis when taken in higher concentrations.
• Parasitic gastroenteritis – This occurs when parasites infect the gastrointestinal tract, leading to inflammation. This condition often causes symptoms such as diarrhea, stomach cramps, and vomiting.
• Toxins-induced gastroenteritis – It occurs when harmful toxins from bacteria like Staphylococcus aureus or Bacillus cereus infect the digestive system. This type of illness results from consuming improperly stored or undercooked food.

Gastroenteritis Symptoms

Gastroenteritis attacks the intestines, leading to early symptoms such as:

• Loss of appetite
• Nausea, vomiting, and diarrhoea
• Abdominal pain and cramps
• Diarrhoea with bloody stools or pus
• General discomfort, including fatigue and body aches

Stages of Gastroenteritis

Symptoms of gastroenteritis often appear suddenly. Many people experience frequent diarrhea or vomiting on the first day. Symptoms typically develop one to two days after exposure to the virus and usually resolve within a couple of days.

The progression of gastroenteritis includes:

1. Exposure: The risk of contracting gastroenteritis is higher in enclosed spaces like schools and nursing homes.
2. Incubation Phase: Once the virus enters the body, it begins replicating. Symptoms do not appear until the virus has multiplied enough to trigger an immune response, usually within a few days.
3. Acute Infection: The immune system detects the virus and launches an inflammatory response, causing symptoms such as vomiting and diarrhea.
4. Recovery: As the immune system fights off the virus, symptoms gradually improve. However, the virus may still be present in feces for a few days, meaning the person remains contagious.

Causes of Gastroenteritis

Several viruses can infect the gastrointestinal tract and cause gastroenteritis. The most common include:

• Norovirus: The leading cause of adult gastroenteritis, responsible for about 50% of cases worldwide. It is highly resistant to disinfectants and extreme temperatures.
• Rotavirus: The primary cause of gastroenteritis in children. Most adults are immune due to early childhood exposure. A vaccine is available.
• Astrovirus: Mainly affects children under three, spreading through childcare centers and, in some cases, elder care facilities.
• Adenovirus: This is commonly linked to respiratory infections but can also cause gastrointestinal infections in people of all ages.

Other causes of gastroenteritis include:

• Bacteria (e.g., Campylobacter)
• Bacterial toxins: Some bacteria release toxins that contaminate food, such as Staphylococcus aureus.
• Medications: Certain antibiotics can trigger gastroenteritis in sensitive individuals.
• Chemicals: Exposure to toxins like lead poisoning can lead to gastroenteritis.
• Contaminated seafood and water: Raw or undercooked oysters and tainted water sources can cause viral diarrhea.

Complications of Gastroenteritis

The primary complication of gastroenteritis is dehydration, which results from excessive fluid loss. Healthy individuals can usually replenish lost fluids by drinking water. However, newborns, the elderly, and people with weakened immune systems face a higher risk of severe dehydration, which sometimes requires hospitalization and IV fluids. In rare cases, dehydration can be fatal.

Prolonged gastroenteritis may cause intestinal damage, such as bleeding ulcers. While most cases resolve quickly, some forms can persist longer.

When to Seek Medical Attention?

Certain symptoms require immediate medical care. Contact a doctor if you or your child experience:

For Adults:

• Unusual irritability, confusion, or fatigue
• Persistent diarrhea lasting more than two days
• High fever
• Frequent vomiting
• More than six loose stools per day
• Severe abdominal or rectal pain
• Black, tarry, or bloody stools
• Signs of dehydration (e.g., dry mouth, dark urine, excessive thirst)

For Infants and Young Children:

• Unusual lethargy or irritability
• Diarrhea lasting more than a day
• High fever (any fever in infants)
• Frequent loose stools or vomiting
• Severe abdominal pain
• Dehydration signs (e.g., dry mouth, fewer wet diapers, no tears when crying)
• Black, tarry, bloody, or pus-filled stools

Gastroenteritis and Children

Children are more susceptible to dehydration, so monitoring symptoms is crucial. Look for signs like excessive thirst, dry lips, and dry skin. Children with gastroenteritis should stay home from daycare or school until symptoms subside. Always consult a doctor before giving medications, as anti-diarrheal or anti-nausea drugs are generally not recommended for children under five.

Risk Factors for Gastroenteritis

While gastroenteritis can affect anyone, certain factors increase the risk:

• Being younger than six or older than 65
• Living or working in a group setting (e.g., nursing homes, schools)
• Consuming raw or undercooked meat or seafood
• Traveling to developing regions
• Having a weakened immune system due to chronic illness
• Regularly consuming alcohol or certain medications

Recovery Expectations and Warning Signs

In most cases, gastroenteritis resolves itself within a few days. However, if symptoms persist, seek medical attention. People with weakened immune systems may need medication for symptom relief or dehydration treatment. If symptoms do not improve, another underlying illness could be the cause.

Frequently Asked Questions