Stomach bug in adults, diarrhea and food poisoning: online treatment in Puerto Rico

A stomach bug (gastroenteritis) is an infection of the stomach and intestines, usually caused by a virus. Although it is called "stomach flu", it isn’t caused by the flu virus. The most common cause of diarrhea in adults is norovirus, which is highly contagious and causes outbreaks in hospitals, schools and on cruise ships. In young children, rotavirus is the leading cause. COVID-19 can also cause stomach symptoms.

It spreads through contact with a sick person, contaminated food or water, and shared surfaces and utensils. Most people with norovirus get better within 1 to 3 days. Older adults and people with weakened immune systems are at higher risk of complications.

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A stomach bug is handled in a doctor visit, the same price for every age, with no membership. You pay by card when you request the visit, and you get a full refund if the clinic can’t see you. A doctor’s note after your visit is included at no extra charge.

We do not bill insurance; the lab and the pharmacy charge separately. See all prices. The service is run by The Health Initiative, a nonprofit.

Symptoms usually start 4 to 48 hours after exposure. The most common are:

• Diarrhea
• Vomiting
• Nausea
• Belly pain or cramps
• Fever
• Headache and body aches

The most important thing is replacing lost water and salts. Drink an oral rehydration solution (an electrolyte solution from the pharmacy) in small, frequent sips, following the label; drinking a lot at once can bring on more vomiting. Skip juice, soda, flavored gelatin and broth: they don’t replace lost salts. If you are an older adult or have diabetes, kidney disease or another health condition, check with a doctor before using an oral rehydration solution. When you are hungry, eat small amounts often: cereals, bread, potatoes, lean meat, plain yogurt, bananas and vegetables.

Antibiotics don’t work against viruses. According to the National Institutes of Health (NIDDK), adults can treat acute diarrhea with over-the-counter loperamide or bismuth subsalicylate, but they are not recommended if you have bloody stools or a fever, and you should see a doctor if diarrhea gets worse or lasts more than 2 days while you take them. Probiotics are still being studied, and many medical societies say the evidence does not support using them for diarrhea. If you take a diuretic (water pill), ask whether to pause it; never stop a prescription medicine without checking.

If vomiting keeps you from drinking oral rehydration solution, the doctor may consider ondansetron, a prescription medicine for nausea. If appropriate, the doctor prescribes something for nausea or another symptom and we send your prescription to your pharmacy.

If diarrhea lasts several days, has blood in it, or the doctor suspects bacteria or a parasite, we give you a lab order for a stool test at a lab near you and review the result with you.

Wash your hands with soap and water for at least 20 seconds, especially after using the bathroom and before handling food: hand sanitizer doesn’t work well against norovirus. Clean surfaces with a bleach solution (5 to 25 tablespoons of household bleach per gallon of water) and leave it on for at least 5 minutes. Don’t prepare food for others until 48 hours after your symptoms stop.

After a hurricane or flood, drink bottled, boiled or treated water. To boil it, the CDC says to bring clear water to a rolling boil for 1 minute. If there is a boil water advisory in your area, follow those steps.

In Puerto Rico, vomiting 3 or more times in 24 hours, together with belly pain, is also a dengue warning sign, especially after a few days of fever. Read dengue warning signs.

Food poisoning causes almost the same symptoms: diarrhea, stomach pain or cramps, nausea, vomiting and fever. According to the CDC, how soon it starts depends on the germ: 30 minutes to 8 hours for staph toxin, 6 hours to 6 days for Salmonella, and up to 2 weeks for Listeria. So it was not always "the last thing you ate".

If you got sick after eating reef fish such as barracuda, grouper or snapper and you also have tingling or cold things feel hot, it may be ciguatera, which is not a virus and is not destroyed by cooking. If it started while traveling, read traveler's diarrhea. Visitors with food poisoning in San Juan or anywhere on the island can be seen by video.

The NIDDK defines diarrhea as loose, watery stools three or more times a day, or more often than is normal for you. Acute diarrhea usually lasts less than a week and goes away on its own; its most common causes are viral gastroenteritis, food poisoning and medicine side effects, such as some antibiotics.

Diarrhea that lasts 2 to 4 weeks (persistent) or 4 weeks or more (chronic) has other causes: infections such as *C. difficile* after antibiotics, parasites, lactose intolerance, celiac disease, Crohn’s disease, ulcerative colitis or irritable bowel syndrome. In those cases the doctor evaluates you by video, gives you any lab order you need and, if an in-person workup is needed, refers you.

If diarrhea started while traveling or after you arrived on the island, read traveler's diarrhea.

The NIDDK says an adult with diarrhea should talk with a doctor right away for any of these:

• Diarrhea for more than 2 days
• High fever
• Six or more loose stools in 24 hours
• Frequent vomiting
• Severe pain in the belly or rectum
• Signs of dehydration: strong thirst, dry mouth, little or no urine, dark urine, dizziness or weakness

Bloody diarrhea, black tarry stools or stools with pus need in-person care the same day (emergency room or urgent care center); if you are also dizzy, confused or in severe pain, go to the emergency room or call 911. People who are pregnant, over 65, taking antibiotics or immunocompromised should stay in close touch with a doctor.

With no emergency signs, the doctor evaluates you by video. Doctor online 24/7: video visits any time, including nights and weekends.

This page is for adults. We also see children of all ages, but babies and young children dehydrate faster and the warning signs depend on age: see our page on diarrhea and vomiting in children. Don’t give children over-the-counter diarrhea medicines.

The doctor evaluates your child by video with you on camera. Patients under 21 need a parent or legal guardian on camera with ID. See our online doctor for kids.

For safety: a baby under 3 months with a temperature of 100.4 °F (38 °C) or higher needs the emergency room right away.

These signs can mean serious dehydration or another cause that needs care right away. For your safety, go to the emergency room or call 911. See when to go to the ER.

• Blood in the stool or vomit
• Can’t keep fluids down
• No urine for 8 hours or more
• Dizziness or fainting when standing up
• Confusion or unusual drowsiness
• Severe, constant belly pain
• Vomiting 3 or more times in 24 hours after days of fever (possible dengue)