Acute diarrhea is characterized by passing loose or watery stools more than three times a day, lasting less than 14 days. Common causes include viral infections (such as norovirus, rotavirus), bacterial infections (salmonella, shigella, campylobacter, toxin-producing e.coli), parasites, or medication side effects.

Doctor Nguyen Thanh Huyen Van, a specialist in Gastroenterology at the Endoscopy and Gastrointestinal Endoscopic Surgery Center, Tam Anh General Hospital, TP HCM, stated that acute diarrhea is often mild, but if not treated promptly, it can lead to dangerous complications.

Dehydration and electrolyte imbalance

When diarrhea is accompanied by vomiting, the body loses large amounts of water and electrolytes such as sodium, potassium, chloride, and bicarbonate. Hypokalemia (low potassium) can cause muscle weakness, fatigue, and dangerous heart rhythm disturbances. Hyponatremia (low sodium) or hypernatremia (high sodium) can lead to altered consciousness, seizures, and coma if left untreated.

Acute kidney injury

Prolonged dehydration reduces circulating volume and blood flow to the kidneys, causing acute kidney injury. This complication is more common in the elderly, individuals with cardiovascular disease, or those using diuretics.

Patients may exhibit signs such as reduced urination accompanied by increased blood creatinine levels. If fluid resuscitation and hemodynamic adjustments are not made promptly, acute kidney injury can progress to structural kidney damage.

Doctor Huyen Van examines a patient. Photo: Tam Anh General Hospital

Sepsis

Some bacteria causing diarrhea can invade the intestinal lining and then enter the bloodstream, leading to sepsis. According to Doctor Van, this is a severe, life-threatening complication if not treated early. Patients often present with high fever, chills, extreme fatigue, and low blood pressure.

Metabolic acidosis

Prolonged diarrhea causes the body to lose significant bicarbonate through stool, leading to metabolic acidosis. This increases the acid environment in the blood, affecting the function of multiple organs. Patients may experience fatigue, nausea, rapid or deep breathing. In severe cases, metabolic acidosis can cause cardiovascular and neurological dysfunction.

Hemolytic-uremic syndrome (HUS)

This is a rare but serious complication, often associated with shiga toxin-producing e.coli infection. HUS is characterized by hemolytic anemia, thrombocytopenia, and acute kidney injury. This complication is more common in children but can also occur in adults. If not treated promptly, HUS can lead to severe kidney failure and systemic complications.

According to Doctor Van, acute diarrhea can destabilize existing chronic conditions such as heart failure, coronary artery disease, or diabetes. Dehydration increases blood viscosity, promoting clot formation in individuals with cardiovascular disease. People using diuretics, angiotensin-converting enzyme inhibitors, or hypoglycemic agents are prone to homeostatic imbalance if diarrhea is prolonged.

Doctors advise individuals with acute diarrhea to rehydrate and replenish electrolytes early, using oresol solution prepared according to instructions. Oresol contains glucose and electrolytes, which enhance sodium absorption through the sodium-glucose co-transport mechanism in the intestines. If oresol is unavailable, diluted rice porridge, soup, or fresh coconut water can be used temporarily for rehydration. However, carbonated soft drinks or beverages containing excessive sugar should be avoided, as they can worsen symptoms.

Patients should seek medical attention if they experience signs such as frequent diarrhea throughout the day, high fever, severe abdominal pain, bloody stools, or diarrhea lasting more than three days without improvement. Young children, the elderly, or individuals with underlying health conditions should seek earlier examination for timely assessment and treatment.

Thao Nhi