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Gastrointestinal (GI) illnesses often give you unpleasant symptoms like nausea, diarrhea or fever. At MedExpress, we treat a number of GI illnesses to get you back to feeling well.


What are Gastrointestinal or Digestive Illnesses?

GI diseases and illnesses are any ailments linked to the digestive system, including the throat, stomach and intestines. Diagnoses may include acute, short-term illnesses — sometimes referred to as "stomach bugs." They can give you unpleasant symptoms while they work their way through your system.

GI diseases may also include more chronic diagnoses, such as Crohn’s disease or irritable bowel syndrome (IBS), and may require long-term, specialty treatment.

There are several different types of GI illnesses, including viral gastroenteritis, food poisoning and even constipation. On this page, you’ll learn more about some of the most common short-term GI illnesses we see at MedExpress.

Did you know? The National Institutes of Health reports that between 60 and 70 million people are affected by digestive diseases each year.1

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Symptoms of Gastrointestinal Illnesses

Most GI ailment symptoms are easily recognizable. GI disorders often begin with abdominal discomfort and nausea and then symptoms may differ depending on your specific ailment. GI disorders or infections may include:

Viral Gastroenteritis (“Stomach Flu”)
Viral gastroenteritis is a digestive illness commonly referred to as "stomach flu" − but it isn’t actually flu at all. True flu only refers to influenza, a virus affecting your respiratory system. Rather, viral gastroenteritis is an infection that affects your intestines. You can contract it by coming in contact with someone who already has the ailment or by ingesting food or water that's been contaminated with a virus, like norovirus.

Gastroenteritis symptoms may take several days to appear, though they normally don't linger for more than a day or two. Exceptions may be those with rotavirus, whose symptoms can last up to nine days, and norovirus, which can last one to three days. Symptoms include:

  • Vomiting
  • Watery diarrhea
  • Cramping
  • A low fever
  • Nausea

Food Poisoning 
Food poisoning is an illness which occurs when you've eaten food contaminated by an infectious organism, such as salmonella, listeria or E. coli. This can occur with undercooked or improperly handled food. Symptoms typically appear eight to 12 hours after eating and can last for one to two days. Food poisoning begins with abdominal cramping. Other symptoms include: 

  • Nausea
  • Vomiting
  • Diarrhea
  • Fever
  • Cramps

Gastrointestinal Infections
Gastrointestinal infections can be caused by viruses, bacteria, or parasites that settle in your GI tract. Viral and bacterial infections normally resolve in a few days, whereas parasitic infections typically will require medical treatment to resolve. Symptoms include:

  • Diarrhea
  • Abdominal discomfort
  • Vomiting
  • Those with parasites, particularly pinworms (common among school-age children) may experience difficulty sleeping, restlessness and itching around the infection site.


A common, usually temporary disorder, often the result of inactivity, eating or drinking a lot of dairy products, and/or not having enough fiber or water in your diet. Constipation may resolve itself within a few days. Symptoms include:

  • Trouble with bowel movements 
  • Bloating

Morning Sickness

Many pregnant women suffer from morning sickness, which (despite its name) can occur at any time of the day. Typically occurring during the first trimester of pregnancy, morning sickness is also not a true “sickness” but rather the result of fluctuating hormones in a woman's body. Symptoms include:

  • Nausea 
  • Vomiting 

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Diagnosing Gastrointestinal Illnesses

Because there are a multitude of diagnoses that fall under GI illnesses, your MedExpress medical team may ask you about your symptoms and recent activities, among other things, to help them make their diagnosis.

Patients may be referred to a gastroenterologist for chronic disorders. Specialists may be able to help the patient determine how to adjust their lifestyle, diet, medications, or manage their ongoing symptoms. In cases where serious underlying disorders are suspected by your health care provider, immediate referral to the emergency department may be necessary.

Treating a GI Disorder

Though specific treatments vary depending on the diagnosis, general care of stomach or digestive trouble may include:

  • Resting and drinking plenty of fluids. 
  • Following the BRAT diet – bananas, rice, applesauce and toast – all of which are easy on the stomach and beneficial in their own way. At the same time, avoid things like dairy, grease, and spices, as they can aggravate your digestive system. 
  • Taking over-the-counter medications to ease symptoms (for example, laxatives for constipation). 
  • Upon being examined by a medical provider, medications could be prescribed to control symptoms such as nausea to provide comfort and aid in the ability to rehydrate. When appropriate, anti-nausea medications and/or IV rehydration may be administered.


1 National Institute of Diabetes and Digestive and Kidney Diseases: Digestive Diseases Statistic for the United States Published: Nov. 2014. Last accessed: March 16, 2023.

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