The common cold is a familiar respiratory illness, and many people wonder if it can also cause digestive issues like diarrhea. While the common cold primarily affects the upper respiratory system, experiencing both sets of symptoms can also be confusing. A direct link between a typical common cold virus and diarrhea is not straightforward.
What is the Common Cold?
The common cold is an infection of the nose and throat, most frequently caused by rhinoviruses, accounting for 30% to 80% of adult colds. Other viruses like coronaviruses (excluding SARS-CoV-2), respiratory syncytial virus (RSV), and parainfluenza viruses can also cause it. Symptoms include a runny or stuffy nose, sore throat, cough, sneezing, and sometimes mild fatigue. These symptoms are generally localized to the respiratory tract.
The common cold typically resolves within 7 to 10 days. Digestive symptoms like diarrhea or vomiting are not characteristic of infections caused by primary common cold viruses. The immune response focuses on clearing the infection from the airways.
Viruses That Cause Both Cold-Like Symptoms and Diarrhea
While typical common cold viruses do not cause diarrhea, other viruses can present with cold-like symptoms and gastrointestinal distress. Influenza viruses, for example, cause respiratory symptoms like cough, sore throat, fever, body aches, and fatigue. Some influenza infections, particularly in children, may also cause vomiting and diarrhea. These are distinct from the rhinoviruses that cause the common cold.
Adenoviruses can cause respiratory infections resembling a common cold, with symptoms like congestion, cough, and sore throat. They are also a common cause of acute gastroenteritis, involving diarrhea, vomiting, and abdominal pain. This symptom overlap can make distinguishing between a cold and an adenovirus infection difficult for individuals.
Enteroviruses, a broad group, cause various illnesses, including mild respiratory infections with cold-like symptoms. Some can also infect the gastrointestinal tract, leading to diarrhea, nausea, and vomiting. Coxsackieviruses, a type of enterovirus, cause hand, foot, and mouth disease, which may include mild fever, sore throat, skin lesions, and occasionally diarrhea. The presence of both respiratory and digestive symptoms can indicate an infection with these broader viral groups rather than a simple common cold.
Other Reasons for Diarrhea During a Cold
Diarrhea occurring with cold symptoms does not always mean the cold virus is the cause. Other unrelated factors can lead to digestive upset at the same time. Bacterial infections, like food poisoning, can independently cause diarrhea, abdominal cramps, and nausea. These are acquired through contaminated food or water and are separate from a viral respiratory illness.
Medications for cold symptoms can contribute to digestive issues. Some over-the-counter cold remedies, for instance, might have a mild laxative effect. If a secondary bacterial infection develops, antibiotics may be prescribed, which are well-known for causing diarrhea as a common side effect. Antibiotics can disrupt the gut’s natural balance of beneficial bacteria, leading to digestive upset.
Changes in diet or increased stress during illness can also affect the digestive system. Feeling unwell might lead to different food choices or increased stress, both causing temporary digestive disturbances. These environmental and physiological factors can coincidentally result in diarrhea while someone has cold symptoms.
When to Consult a Doctor
It is advisable to consult a healthcare professional if diarrhea with cold symptoms becomes severe or persistent. Signs of dehydration, such as decreased urination, excessive thirst, or dizziness, warrant medical attention. A high fever (above 102°F/39°C), especially if persistent for several days, is another reason to seek advice.
Blood or black, tarry stools indicate a serious underlying issue and require immediate medical evaluation. Persistent or severe abdominal pain, or vomiting that prevents keeping fluids down, are also concerning symptoms. If symptoms worsen or do not improve after a few days, consult a doctor to rule out more serious conditions.