How Colds Can Lead to Diarrhea Through Virus Spread and Inflammation

How Colds Can Lead to Diarrhea

Colds are viral respiratory infections that often cause symptoms like sore throat, stuffy nose, cough, and congestion. But colds can sometimes manifest with digestive issues like nausea, vomiting, and diarrhea.

Its not entirely clear why colds may trigger gastrointestinal problems. One theory is that cold viruses like rhinovirus may spread from the respiratory tract to the intestines. Alternatively, the immune system's inflammatory response to a cold virus could stimulate nerves that influence gut function.

While diarrhea from a cold virus is not extremely common, knowing why it happens and what you can do to find relief from this frustrating symptom can help you get through an illness.

Cold Virus Spread to the Gut

Viruses that infect the respiratory system, like adenovirus and coronavirus, have also been detected in stool samples. This suggests gastroenteritis can result from the spread of cold viruses from the upper respiratory tract to the intestines.

For some pathogens like norovirus, its well established they directly invade the GI tract leading to vomiting and diarrhea. More research is needed to determine if cold viruses directly infect intestinal cells and damage the gut, or if they cause diarrhea through other mechanisms.

Immune Response and Nerves Trigger Diarrhea

Some scientists suspect that cold viruses prompt diarrhea because the immune system reacts to the infection by triggering intestinal nerves that control digestion and gut movement.

Inflammatory molecules released by immune cells to fight cold viruses activate vagus nerve fibers and enteric nerves in the digestive tract. This stimulates muscle contractions, intestinal secretion of fluid, and increased motility speeding up transit time - changes that together result in loose watery stools.

Over 700 Cold Viruses

Colds can be caused by any one of over 200 related viral subtypes, although rhinoviruses are the most common culprit. Cold viruses evolve rapidly so new strains emerge each year accounting for seasonal outbreaks. Transmission peaks in winter and spring in temperate regions when viruses survive better in cold dry air.

Cold viruses are passed person-to-person through contact with infected nasal secretions, including airborne droplets from coughs and sneezes. Viruses enter the body through mucous membranes when you touch your eyes, nose or mouth after contact with contaminated surfaces or hands.

People infected with a cold are generally contagious for about a week as viruses incubate and multiply. But you're often spreading viruses for a few days before realizing youre sick. Young kids tend to be major spreaders of colds because of their close interactions and lack of hygiene.

Cold Symptom Differences

Colds caused by one of the hundreds of cold viruses produce similar discomforts. Symptoms arise around two days after exposure as your immune system reacts to the infiltration and replication of viruses in the nose and throat.

Early signs include sore scratchy throat, runny nose, sneezing, mild headache, and cough due to inflammation and swelling from immune response. Later on, thick discolored mucus develops and congestion may cause ear pressure, decreased smell and taste, and hoarse voice.

Fatigue from fighting infection can make you feel generally unwell. Fever and body aches are more common in flu compared to colds. And eye symptoms like redness and discharge are associated with adenovirus colds. Diarrhea only occurs in about 5-10% of colds.

Duration of Cold Symptoms

How long cold symptoms last varies depending on age, health status, virus strain, reinfection, and other factors. For otherwise healthy adults, worst symptoms typically resolve in 7 to 10 days. But lingering coughs can persist up to three weeks even after other symptoms end.

Young children often take a little longer than adults to recover from cold symptoms, especially coughs which can worsen and last for weeks. Reinfection with new cold strains leads to more drawn out illnesses.

Elderly people and those with weakened immune systems dont fight off cold viruses as readily. They often suffer worse and more persistent symptoms along with higher risks for complications like pneumonia.

Diarrhea Caused by Colds

Gastrointestinal issues are fairly uncommon with colds, only occurring in around one in twenty people. But bouts of loose watery stools, urgent bowel movements, stomach pain and nausea can happen when cold viruses impact digestion.

Virus Spread From Respiratory Tract to Gut

Coronavirus, rhinovirus, adenovirus, and other cold viruses likely make their way to the digestive system by being swallowed in mucus drained from the upper airways. Viruses may then infect and damage intestinal cells disrupting normal absorption of water resulting in diarrhea.

Inflammation Triggers Gut Spasms and Fluid Secretion

A runny nose isnt the only symptom triggered by inflammation-inducing cytokines unleashed by the immune system in response to a cold virus. An inflammatory reaction in the gut can stimulate intestinal nerves and muscle contractions while promoting secretion of watery fluid leading to diarrhea.

Altered Gut Microbes May Contribute

Another theory is that changes in intestinal bacteria during a viral illness enable certain microbes to dominate that irritate the GI tract. This proinflammatory effect may interact with infection-fighting molecules and nerves to stimulate diarrhea.

Medications Can Cause Diarrhea Too

Finally, over-the-counter cold medications like expectorants and cough syrups have diarrhea or loose stools as a common adverse side effect. The ingredients guarana, phenylephrine, and dextromethorphan seem most frequently linked to this symptom.

Treating Cold Virus Diarrhea

Cases of diarrhea resulting from a cold virus tend to be mild and resolve along with other symptoms in a week or so. But passing frequent watery stools can contribute to dehydration and discomfort.

Treating symptoms and staying hydrated will help you get through a GI illness. Over-the-counter medications can alleviate cramping and diarrhea until your gut recovers.

Get Plenty of Rest

Allow your body to devote its energy toward fighting infection by getting extra rest. Take a sick day from responsibilities if possible. Sleep, relax with soft foods and fluids, and don't overexert yourself.

Stay Hydrated

Frequent loose bowel movements result in the loss of fluids and electrolytes like sodium and potassium. Drink extra liquids like water, broths, or electrolyte beverages. Take small frequent sips if larger amounts upset your stomach.

Eat Gentle Foods

Give your digestive tract a break by avoiding irritating foods for a couple days. Stick to bananas, rice, applesauce, and toast until acute gastroenteritis symptoms resolve. Then slowly reintroduce your normal diet.

Consider Over-the-Counter Anti-diarrheals

Medications that slow GI motility like loperamide (Imodium) allow more time for water reabsorption. Those with absorbents like bismuth subsalicylate (Pepto-Bismol and Kaopectate) soothe inflammation. These can relieve diarrhea for 6-12 hours.

Take OTC anti-diarrheals as directed on the label. Avoid giving these medications to children under age twelve without first consulting a pediatrician.

Seek medical care if you experience no improvement in diarrhea, vomiting, pain or dehydration after 24 hours - especially infants, elderly and those with chronic diseases or compromised immunity.

Can Probiotics Help Diarrhea from Colds?

Some clinical research indicates probiotic supplements may reduce the incidence of diarrhea associated with upper respiratory infections. Certain strains of beneficial gut bacteria seem to stimulate immune responses that interfere with virus replication in the intestines.

Results from some studies show fewer days with watery stools and less gastroenteritis symptoms with probiotic use versus placebo. The probiotic yeast Saccharomyces boulardii displays consistent anti-diarrheal effects across multiple trials.

If you already take a probiotic, continue usage as this may offer slight protection against diarrhea. But introducing new supplements with live bacteria during an illness could further disrupt your microbiome. Get your doctors input before starting probiotics.

Probiotic foods like yogurt, kefir and fermented vegetables provide nourishment with less risk of adverse effects compared to concentrated capsules. Prebiotic fiber feeds good gut microbes and may safely ease diarrhea when slowly introduced to your diet.

Preventing Diarrhea When You Have a Cold

You cant always avoid catching a cold virus, but practicing good hygiene and healthy habits may reduce your chances of accompanying diarrhea and gastrointestinal issues.

Wash Your Hands Frequently

Thoroughly cleaning hands with soap and water helps remove contagious viruses you contact from people and contaminated surfaces. Alcohol sanitizers also work when soap isnt available.

Dont Touch Your Face

Keep hands away from your eyes, nose, and mouth to block viruses from entering mucous membranes. This simple behavior minimizes transfer of germs from hands to areas where cold viruses can gain entry.

Sanitize Surfaces

Cold viruses can survive up to a week on hard surfaces. Regularly disinfect doorknobs, phones, remote controls, keyboards and other household items to destroy lingering viruses and prevent reinfection.

Avoid Close Contact with Sick People

Try to stay three to six feet away from anyone showing symptoms of respiratory illness like coughing and sneezing which spray contagious microbes. Avoid hugging, kissing, shaking hands or sharing food or drinks.

Don't Smoke or Vape

Inhaling smoke, fumes and vapors irritates airway tissues making it easier for cold viruses to establish infection. Damaging lungs also impairs immune defenses leaving you prone to more severe or lasting cold symptoms.

Staying healthy with good hygiene, nutrition, adequate sleep and stress control bolsters immunity and may lessen your chances of getting sick. But even if you still catch a cold virus, preventing transmission to your gut avoids miserable diarrhea.

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a healthcare professional before starting any new treatment regimen.