Food poisoning is an unpleasant experience that many of us have encountered at some point in our lives. Whether it's a mild case that resolves quickly or a more severe bout requiring medical attention, understanding the ins and outs of food poisoning can help us better manage symptoms, recover effectively, and prevent future episodes.

We spoke with Amit Desai, M.D., a gastroenterologist and physician on the medical staff at Texas Health Plano and at Texas Digestive Disease Consultants, to address some common questions and concerns surrounding food poisoning.

Understanding Food Poisoning

Food poisoning, often referred to as a foodborne illness, occurs when we ingest contaminated food or beverages. This contamination can arise from various sources, including bacteria, viruses, parasites, or toxins produced by microorganisms. Upon consumption, these pathogens wreak havoc on our gastrointestinal tract, leading to symptoms such as vomiting, diarrhea, abdominal pain, and nausea.

“Although we think of it generally as food poisoning, this is usually triggered by an infection,” Desai explains. “I think most patients may not realize this is really just an infection, similar to an upper respiratory infection, a common cold, etc. And usually, those go away without needing antibiotics. That same idea works for foodborne illnesses.”

Numerous pathogens can trigger food poisoning, with some of the most common culprits including Norovirus, Salmonella, E. coli, Campylobacter, and Giardia. The symptoms you encounter will vary based on which pathogen you have, while many will have similar symptoms.

• Norovirus: This highly contagious virus spreads through contaminated food, water, or surfaces. It's known for causing outbreaks of gastroenteritis, or stomach flu, with symptoms like nausea, vomiting, diarrhea, and abdominal pain.
• Clostridium perfringens: Found in soil and intestines, this bacterium produces toxins causing abdominal cramps and diarrhea when eating contaminated meats or meat products.
• Escherichia coli (E. coli): While most types are harmless, certain strains like E. coli O157:H7 can cause severe food poisoning. It's commonly found in undercooked ground beef, raw fruits, vegetables, and unpasteurized dairy.
• Giardia: This parasite infects intestines through contaminated water, food, or surfaces, leading to symptoms like diarrhea, abdominal cramps, and nausea.
• Campylobacter: These bacteria are a top cause of bacterial gastroenteritis worldwide. Eating undercooked poultry, unpasteurized milk, or contaminated water can lead to infection.
• Shigella: Shigella bacteria cause shigellosis, a foodborne illness with severe diarrhea, fever, and stomach cramps. It spreads through poor hygiene and contaminated food or water.
• Salmonella: Commonly causing food poisoning, Salmonella is contracted through contaminated eggs, poultry, meat, dairy, or produce, resulting in diarrhea, fever, and abdominal cramps.

Desai adds that the onset of symptoms will also depend on the type of pathogen involved. While pre-formed toxins can induce a rapid onset of symptoms, bacterial and viral infections may take hours or even days to manifest. However, symptoms typically start to improve within a few days for most individuals, with complete recovery occurring within a week.

Less often food poisoning affects the nervous system and can cause severe disease. Symptoms may include:

• Blurred or double vision.
• Headache.
• Loss of movement in limbs.
• Problems with swallowing.
• Tingling or numbness of skin.
• Weakness.
• Changes in sound of the voice.

“Patients with an inability to maintain adequate hydration, bloody diarrhea, persistent fever greater than 101.4, symptoms longer than a week, severe abdominal pain or if you’re considered ‘high risk’ should seek medical care right away,” Desai says.

High-risk individuals include those over 70 years of age, those who have compromised immune systems, those with inflammatory bowel disease, and those who are pregnant.

Managing Symptoms and Recovery

Most of the time, symptoms of food poisoning can be managed at home. This primarily focuses on rehydration and symptom relief. While it may seem counterintuitive, Desai suggests avoiding anti-diarrheal medications like loperamide (Immodium) when it comes to treating and easing symptoms because they interfere with the body's natural defense mechanisms. Diarrhea, though uncomfortable, helps expel harmful substances from the digestive system. Suppressing diarrhea can prolong the illness by delaying the elimination of toxins. Additionally, slowing down the digestive tract with these medications can increase the absorption of toxins into the bloodstream, potentially worsening the infection.

Furthermore, diarrhea aids in maintaining fluid and electrolyte balance; suppressing it can disrupt these balances, leading to dehydration and electrolyte imbalances, which can already be thrown off if you’re also vomiting.

“The ideal and most critical support is oral rehydration,” Desai explains. “I use electrolyte-balanced solutions such as Pedialyte, or similar rehydration solutions. Soups or broths are also helpful for rehydration. If you also have nausea or vomiting, adding in ginger-based supplements can ease symptoms.”

Desai adds that it’s best to consume fluids slowly throughout the day instead of all at once, which not even be something you’d feel up to anyway.

“If it gets to the point where you cannot drink or keep down anything at all, despite trying, then it is important to seek medical care as some patients may need intravenous hydration for this reason,” he notes.

During and after a bout of food poisoning, sticking to bland, easily digestible foods like the BRAT diet (bananas, rice, applesauce, toast) may help alleviate symptoms.

While most cases of food poisoning resolve with rest, hydration, and nutrition, severe or persistent symptoms warrant medical attention.

Even after you’ve cleared the infection and the worst of it seems over, Desai says it’s not uncommon to experience lingering gastrointestinal issues.

“After an episode of food poisoning, what can happen is the intestines are ‘stunned’ or just don't fully return immediately back to normal,” he explains. “This is commonly a phenomenon called post-infectious irritable bowel syndrome. The main thing to know is most patients return to normal after this and ultimately, it just takes some time to recover.”

Desai suggests sticking to your “comfort foods,” or foods you know you’ve tolerated well in the past, slowly reintroducing foods you typically eat, and relying on supplements like peppermint oil pills or tea in the meantime to find relief.

“Additionally, I recommend trying to cook and eat at home as much as possible during this phase so you can control what you know works best for you,” Desai adds.

And if you typically reach for a probiotic during or after a bout of food poisoning, Desai says that while you may feel a bit better taking one, most studies have been inconclusive and have not shown a benefit.

“Generally, people will get better without the probiotic, so it's not certain the probiotic is helping,” Desai adds. “However, if you want to take one, there is limited downside other than cost.”

Prevention Strategies

Preventing future episodes of food poisoning involves practicing safe food handling, ensuring proper cooking temperatures, and being cautious when consuming raw or undercooked foods. This applies whether you’re dining at home or eating out.

Opt for restaurants with a good reputation for cleanliness and food safety practices. Check online reviews or ratings from health inspection authorities. Additionally, look for signs of proper food handling, such as food being stored at appropriate temperatures, cleanliness of utensils, and the overall hygiene of the establishment.

If taking home leftovers, refrigerate them promptly to prevent bacterial growth, and reheat leftovers thoroughly before consuming.

Ultimately, trust your instincts. If something looks or smells off, or if you feel unsure about the safety of a dish, it's better to err on the side of caution and avoid consuming it.

In addition to the tips above, travelers should exercise caution with ice, mixed drinks, and food prepared with water in international settings.

“Freezing does not always kill all pathogens, so ice is not always safe to consume, and contrary to belief, alcohol does not sterilize a drink, so mixed drinks are not always safe either,” says Desai. “Any sauces or food items made with water can be contaminated. Additionally, raw fruit or chicken salads are very high-risk items to consume internationally. Generally, boiled foods like soups, when uncertain, are going to be safer to consume.”

The Takeaway

While unpleasant, and definitely not how many would choose to spend their time after enjoying a meal, taking time to hydrate, gradually reintroducing foods, and listening to your body's needs are crucial steps in the healing process after food poisoning.

“Just know that things will get better,” Desai concludes. “Try not to rush recovery. Taking time to rest, hydrate the first few days and then slowly advance your diet can go a long way in getting back to normal.”