Does food poisoning always cause nausea, vomiting or diarrhea or can all of these symptoms be absent in a case of food poisoning?

“Food poisoning cannot be diagnosed unless we have a sample of the food and test it for toxins (poisons) which generally takes three to four days,” says Yvette McQueen, MD, emergency medicine physician and CEO of MedQueen LLC, through which she offers travel medicine, urgent care and nutritional consultations via telemedicine to individuals, executives and travel groups.

“Food poisoning or contamination is ‘suspected’ if a person becomes sick and has certain symptoms after a certain time of eating the food,” continues Dr. McQueen.

“We call it gastroenteritis, which means there is inflammation and possible infection of the gastrointestinal (stomach and intestines) tract in the body.

“It can be brought on by irritation, virus or bacteria; and they have been ingested by contaminated food and/or water.”

Symptoms of Food Poisoning Come Suddenly and Severely

“The person will have nausea, vomiting and diarrhea; or sometimes only nausea/vomiting or only diarrhea,” says Dr. McQueen.

“We can test the stool for certain viruses, bacteria and parasites, but once again it will take 3-4 days for the results.”

A case of food poisoning may run its course in less than 24 hours – as far as the symptoms.

“We generally treat the symptoms until the known cause is found.

“The cause is definitely necessary if there is an influx of a people with the same symptoms from the same area: restaurant, daycare, cruise ship, etc.”

Consequences of Severe Gastroenteritis

Dehydration and electrolyte loss is the first possible outcome, says Dr. McQueen. Patients under five and over 65 are particularly at risk.

“The electrolyte loss can cause problems with the heart and kidneys. Rehydration is the key. If persistent diarrhea for 48 hours, they should see their doctor or go to the ED.

“Self-rehydration for mild cases can be done with water, electrolyte replacement drinks (no caffeine), coconut water, or 2% milk. Diabetics should be seen earlier because persistent diarrhea will cause an acid-balance imbalance.”

The next possible consequence is gastritis or bleeding. Dr. McQueen explains, that “persistent vomiting will break blood vessels in the stomach and esophagus, causing red streaks of blood in the vomit material.

“Dark vomit is a sign of possible bleeding in the stomach and possible ulcers; the blood has mixed with the gastric juices in the stomach causing it to have a dark, coffee ground appearance.”

That “coffee ground” appearance that you may have read about many times is more in reference to the textural appearance of the vomitus. You can actually see what appears to be clumps of coffee grounds in the liquid.

Obstruction of the intestines is the next possible consequence. Dr. McQueen explains that “the persistent irritation, inflammation or infection may cause severe swelling of the intestines.

“They will swell, balloon and close off; or even twist. This may cause part of the intestine to not get enough oxygen and die.

“The deadly cause will be if the swollen intestines rupture, spilling the contents in the abdominal cavity and causing infection to spread throughout the body (sepsis).

Dr. McQueen is an emergency physician and “The Travel Doctor.” She is a speaker, author and consultant, provides wilderness emergency care training, and international teaching for the American Heart Association.  
Lorra Garrick has been covering medical, fitness and cybersecurity topics for many years, having written thousands of articles for print magazines and websites, including as a ghostwriter. She’s also a former ACE-certified personal trainer.