OVERVIEW

What is autumn diarrhea?

Autumn diarrhea refers to diarrhea that occurs during the cold seasons of autumn and winter, with vomiting and diarrhea as the main symptoms. Children are more susceptible to autumn diarrhea, while adults are less likely to contract the disease. It is primarily caused by viral infections.

As early as the 1950s, outbreaks of infectious diarrhea occurred among children in China. There were two annual peaks: one in June, July, and August, known as "summer diarrhea," which was found to be mainly caused by diarrheagenic Escherichia coli and dysentery bacilli; the other peak occurred in October, November, and December, termed "autumn diarrhea," for which no pathogenic bacteria could be cultured, leaving the cause unknown for a long time.

It wasn't until 1973 that Australian scholar Bishop discovered virus particles resembling wheels in duodenal mucosal biopsy specimens and stool samples from children with autumn-winter diarrhea using electron microscopy. In 1975, the International Committee on Taxonomy of Viruses named it rotavirus. In 1978, Beijing became the first in China to detect rotavirus in stool samples from children with autumn diarrhea using electron microscopy and immunoelectron microscopy, with a detection rate of 83.8%. This confirmed rotavirus as the primary pathogen of infantile autumn diarrhea in China, marking the beginning of research on viral diarrhea in the country.

Is autumn diarrhea common?

Autumn diarrhea is a very common digestive system disease in children, particularly affecting those under 2 years old. The main pathogen is rotavirus.

With further research, other viruses have also been identified as causes of diarrhea, including norovirus, sapovirus, adenovirus, coronavirus, astrovirus, coxsackievirus, and echovirus.

Does autumn diarrhea only occur in autumn?

Autumn diarrhea is not limited to autumn; it also frequently occurs in winter. It is related to temperature, as cold environments facilitate increased viral replication, which is one of the reasons for the rise in diarrhea cases.

Which department should be consulted for autumn diarrhea?

Pediatrics or pediatric internal medicine.

SYMPTOMS

What are the common symptoms of autumn diarrhea?

Clinical manifestations include diarrhea, vomiting, fever, abdominal pain, loss of appetite, headache, and myalgia.

Symptoms vary by age (young infants may show fewer specific symptoms), change daily, and differ among individuals.

Children may initially experience only diarrhea or vomiting, but the condition can worsen, potentially requiring hospitalization. The most common symptoms are:

• Vomiting: Frequent vomiting, making it difficult for the child to eat.

• Fever: Elevated body temperature above 37.5°C, possibly reaching a high fever of 40°C.

• Diarrhea: Characterized by large amounts of loose, watery stools with little solid matter. Diarrhea typically lasts 3–8 days but may persist for 10–14 days. In severe cases, it may become prolonged or chronic. Without timely rehydration, children may develop signs of dehydration.

What severe symptoms may occur with autumn diarrhea?

Severe autumn diarrhea primarily manifests as dehydration, which may include:

• Oliguria: No urination for several hours, with dark yellow and scant urine output.
• Dry skin, chapped lips, and reduced tears when crying.
• Lethargy: The child may appear listless, not crying, moving, or playing.
• Rapid, labored breathing, appearing exhausted.
• In infants, a sunken fontanelle may also be observed as a sign of dehydration.

What other conditions can autumn diarrhea cause? What serious complications may arise?

Autumn diarrhea may lead to shock due to excessive fluid loss.

Shock occurs when the body lacks sufficient fluids to maintain normal blood circulation. Severe shock can be life-threatening.

However, effective treatments are available today. Only severe diarrhea can cause dehydration, and only untreated severe dehydration may lead to shock. Therefore, there is no need to panic if autumn diarrhea occurs.

CAUSES

What Causes Autumn Diarrhea?

Autumn diarrhea is primarily caused by viral infections, with rotavirus being the main pathogen. Rotavirus is a type of enteric virus that can cause enteritis in both children and adults. Symptoms tend to be more severe in children, while adults may experience mild or no symptoms.

Other viruses can also lead to autumn diarrhea, such as norovirus, sapovirus, adenovirus, coronavirus, astrovirus, coxsackievirus, and echovirus.

After invading the body, the virus replicates in the small intestinal epithelial cells, causing necrosis and shedding of the intestinal mucosa. This impairs intestinal absorption, leaving large amounts of water and undigested food residues in the intestinal lumen, resulting in watery diarrhea.

How Is Autumn Diarrhea Transmitted?

The virus is mainly spread through the fecal-oral route. Infected children or adults serve as sources of transmission. If stool-contaminated hands, toys, or food are ingested by a child, a new infection may occur.

In addition to oral transmission, the virus can also spread through aerosols in the air. Therefore, close contact with an infected person may lead to respiratory transmission of the virus.

DIAGNOSIS

How is autumn diarrhea diagnosed?

• Symptom-based judgment: If a child under 2 years of age experiences vomiting followed by diarrhea, frequent watery stools during the cold season, it is highly likely to be autumn diarrhea.

• Laboratory testing: Diagnosis can involve stool routine tests and rotavirus detection. If the stool routine test shows no evidence of bacterial enteritis (e.g., pus cells) or the rotavirus test is positive, it confirms autumn diarrhea.

What tests are needed for autumn diarrhea?

For suspected mild to moderate cases without severe dehydration, testing is usually unnecessary.

For severe symptoms or differential diagnosis, the following tests may be required: stool routine, fecal occult blood test, stool viral detection, stool culture, blood biochemistry, complete blood count (CBC), CRP, etc.

If physical examination reveals abnormalities, additional tests such as abdominal X-ray, abdominal ultrasound, or head CT may be needed.

• Stool routine and fecal occult blood test: Assess stool condition.

• Stool rotavirus test: Check for rotavirus.

• Stool culture: Detect bacterial presence.

• Blood biochemistry: Identify electrolyte imbalances caused by diarrhea.

• CBC and CRP: Evaluate systemic inflammation.

• Abdominal X-ray, ultrasound, or head CT: Rule out surgical conditions causing vomiting and diarrhea.

TREATMENT

How to Treat Autumn Diarrhea?

For autumn diarrhea, oral rehydration to prevent dehydration is the key to treatment.

• You can give your baby Oral Rehydration Salts III to help replenish lost fluids and electrolytes.
• When symptoms appear early, fluids can be replenished after each episode of vomiting or diarrhea. Estimate the amount based on the volume of vomit or stool, approximately 10 ml/kg, and administer frequently, completing the rehydration within 1–2 hours. Give 5–20 ml every 5–10 minutes, starting with 5 ml and gradually increasing based on the baby's tolerance.
• If dehydration symptoms are already present, a doctor should assess and calculate the required fluid intake.
• If vomiting is severe and the baby cannot take oral rehydration salts or breast milk, intravenous fluids and electrolytes may be necessary to prevent dehydration.

With effective oral rehydration, autumn diarrhea will resolve on its own. If fever is present, antipyretics can be given to help control body temperature. The following medications are generally unnecessary but may be used as needed:

• Zinc Supplementation: Extra zinc during diarrhea can shorten its duration and promote intestinal mucosal repair. Zinc supplementation is not recommended for infants under 6 months, as it may increase vomiting risk. For children over 6 months who may have zinc deficiency due to picky eating, zinc supplements (20 mg daily for 10–14 days) can be considered.

• Probiotics: Probiotics may be considered for children with autumn diarrhea. Although studies vary, multiple systematic reviews confirm that probiotics can slightly shorten the duration of viral diarrhea, such as Lactobacillus rhamnosus.

• Intestinal Mucosal Protection: Adsorbents (e.g., smectite powder) can bind to digestive mucus and toxins, reducing fluid loss. European and Chinese guidelines suggest its use, though the evidence quality is low. If diarrhea is frequent, watery, or contains blood streaks, smectite powder may be used to protect the intestinal mucosa and prevent damage from repeated diarrhea.

Can Autumn Diarrhea Resolve on Its Own?

Autumn diarrhea can resolve on its own. However, if vomiting and diarrhea are severe, timely supportive care is needed to prevent dehydration, which is the key to treatment.

Can Antidiarrheal Medications Be Used for Autumn Diarrhea?

Antidiarrheal medications should not be used.

Drugs that reduce intestinal motility (e.g., loperamide) do not aid recovery and may instead trap pathogens in the gut, worsening the condition.

Are Anti-Inflammatory Drugs Needed for Autumn Diarrhea?

Most cases of autumn diarrhea are caused by viruses, so anti-inflammatory drugs (antibiotics) are ineffective. Antibiotics target bacteria, not rotavirus, and their unnecessary use can disrupt gut flora, exacerbating diarrhea.

Even for bacterial enteritis, antibiotics are not always necessary, as most bacterial diarrhea is self-limiting. Antibiotics are recommended only for dysentery-like diarrhea, suspected cholera with severe dehydration, immunocompromised children, preterm infants, or those with chronic underlying conditions.

When Is Hospitalization Needed for Autumn Diarrhea?

Hospitalization may be considered if the child shows signs of dehydration and cannot eat due to severe vomiting. Immediate hospitalization is required for severe dehydration or shock symptoms (e.g., lethargy, unconsciousness, persistent high fever, convulsions, or no urine output).

If dehydration is present but the child can still eat, oral rehydration at home is sufficient.

DIET & LIFESTYLE

What can children eat when they have diarrhea in autumn? Can they drink milk?

• For infants, breastfeeding can continue if they are already breastfed. Breast milk is beneficial for recovery and does not need to be stopped.

• Formula-fed babies who have not started solid foods can continue with formula feeding. For prolonged cases, low-lactose or lactose-free formula can be chosen.

• Children who have started solid foods can continue eating them. During diarrhea, avoid introducing new foods—only offer foods they have eaten before and tolerated well.

• Children over one year old can eat salty foods; older children can have an unrestricted diet, including grains, meat, yogurt, fruits, and vegetables. Ensure adequate calorie intake, and after recovery, provide extra nutrients to compensate for losses due to illness.

• Avoid foods high in simple sugars, such as carbonated drinks, jelly, canned juice, sweets, and other sugary beverages. Also, avoid high-fat foods.

• If vomiting is severe, stick to milk or liquid foods. Once vomiting stops, gradually reintroduce regular foods like meat, eggs, and vegetables, increasing portions slowly rather than aiming for pre-illness amounts.

When is regular formula feeding not recommended for autumn diarrhea?

Stopping formula feeding is only considered in cases of severe dehydration. If the child does not require hospitalization, the original milk type can be maintained.

If diarrhea persists for over two weeks, consult a doctor to switch to lactose-free formula, as viral infections may temporarily reduce lactase production. Gradually reintroduce regular formula after recovery.

How to prevent infection during autumn diarrhea?

Since the virus spreads through close contact and air, if there are two children at home, the older one may infect the younger. Separate the children, ensure ventilation, and keep toys, clothes, and utensils apart.

Adults should wash hands frequently and take necessary precautions to avoid transmission.

PREVENTION

How to prevent autumn diarrhea?

During autumn and winter, avoid crowded places. Adults should wash hands and change clothes before holding babies after returning home. If there is an infant at home, it is best not to invite friends or relatives with children to visit to prevent infection. If a family member is sick, try to keep them separated from the baby.

Is there a vaccine for autumn diarrhea?

Among common pathogens causing autumn diarrhea, only rotavirus has a vaccine for prevention.

The rotavirus vaccine can prevent rotavirus infection. It is a Category 2 vaccine, meaning parents must pay for it themselves. Currently, rotavirus vaccines are administered orally. Common options include the imported pentavalent rotavirus vaccine and the domestic Group A rotavirus vaccine—either can be chosen, with the pentavalent version being preferred. Vaccination can reduce the risk of autumn diarrhea in babies.

How to prevent dehydration from autumn diarrhea?

During autumn diarrhea, vomiting and watery stools cause the loss of both fluids and electrolytes. Plain water alone cannot correct dehydration. Oral rehydration salts, prepared according to instructions, help the intestines absorb both water and electrolytes, making them an effective way to prevent dehydration.

If the child refuses oral rehydration salts, alternatives like rice water or apple juice can be tried, though their effectiveness may be less reliable. Monitor the child closely, and seek medical attention if symptoms do not improve.