Diarrhea or Stomach Virus: What’s Really Going On

When diarrhea strikes suddenly, it’s easy to assume it’s a stomach virus. However, not all digestive symptoms are caused by an infection, especially when they linger or recur. Understanding the difference between a viral illness and a chronic digestive condition can help you know when to seek care. The gastroenterology experts at NYGA are here to explain how to tell what’s really going on and when it’s time to see a specialist.

Is It a Stomach Virus? How to Tell

Sudden onset of symptoms

A stomach virus, or viral gastroenteritis, typically appears quickly. You may feel fine one moment and develop diarrhea, nausea, or abdominal pain hours later. These infections often follow close contact with someone who is sick or after exposure to contaminated food or surfaces.

Fever, chills & body aches

Unlike many noninfectious causes of diarrhea, viral infections often produce whole-body symptoms. Mild fever, chills, and muscle aches are common, as your immune system mounts a response to the infection. These symptoms help distinguish a virus from conditions like irritable bowel syndrome (IBS) or food intolerance.

Nausea, vomiting, & cramping

Stomach viruses affect the stomach and small intestine, and nausea and vomiting often accompany diarrhea. Abdominal cramping is also common, especially in the first 24–48 hours of illness.

Common Causes of Diarrhea (Beyond a Virus)

Irritable bowel syndrome (IBS)

IBS is one of the most frequent causes of chronic diarrhea. People with IBS-D may experience loose stools, urgency, bloating, and cramping that improve after a bowel movement. Symptoms may fluctuate daily and often worsen with stress, dietary triggers, or hormonal changes. IBS does not cause fever or vomiting, so it can usually be distinguished from a viral illness.

Food intolerance

Food intolerances, such as lactose intolerance, fructose intolerance, or sensitivity to sugar alcohols, can trigger diarrhea soon after eating. These episodes may also cause bloating, gas, and abdominal discomfort, but typically do not cause fever or severe vomiting. Symptoms often occur after repeated exposure to a trigger food.

How long should diarrhea last?

Diarrhea from a stomach virus usually resolves within one to three days, although some infections may last up to a week. When diarrhea continues beyond this window or comes and goes over time, it may signal an underlying condition that needs evaluation. Persistent symptoms can lead to dehydration, fatigue, and nutritional imbalances, so monitoring your fluid intake is essential.

Treating Diarrhea

Treatment depends entirely on the cause. Viral diarrhea typically improves with hydration, rest, and electrolyte replacement. Chronic diarrhea related to IBS may respond to dietary adjustments, stress management, or medications that regulate gut motility. Food intolerances often improve once trigger foods are identified and removed, sometimes with support from a registered dietitian.

When to See a Gastroenterologist in NYC for Diarrhea

You should seek medical evaluation if diarrhea lasts longer than three to five days, recurs, or is accompanied by concerning symptoms such as blood in the stool, severe abdominal pain, dizziness, dehydration, or unexplained weight loss. Patients with a history of IBS, IBD, celiac disease, or food intolerances should also consult a gastroenterologist when symptoms change or worsen.

Take Control of Your Digestive Health

Understanding what’s behind your symptoms is the first step toward feeling better. Whether your diarrhea is caused by a short-lived stomach virus or a chronic gastrointestinal condition, NYGA’s expert gastroenterologists are here to help you get answers and relief.

 

Don’t wait—prioritize your health today.