Bloating, diarrhea, and nausea are three common gastrointestinal (GI) symptoms that can indicate many different conditions.

They frequently occur together or individually.

Short-term GI symptoms are often related to a mild condition such as a stomach bug or eating food that disagrees with you.

If your symptoms are severe or chronic, you may have a more serious condition.

Let’s examine some of the reasons adults might experience these three GI symptoms.

Bloating, nausea, and diarrhea can have many causes. Here are some of the potential reasons you may experience them.

Eating too much fiber

Eating plenty of fiber is essential for maximizing your GI health. However, too much fiber can be difficult to digest. Consuming too much fiber can cause:

Learn about how much fiber is too much.

Food intolerance

Having a food intolerance means your body can’t digest a certain food. A food intolerance may also be called a food sensitivity. Unlike food allergies, a food intolerance is not caused by an overreaction of your immune system.

Food intolerance can cause symptoms such as:

The most common food intolerance is lactose intolerance. Other common intolerances include:

Celiac disease

Celiac disease is an autoimmune disease triggered by the consumption of gluten. It can cause symptoms such as:

Irritable bowel syndrome (IBS)

IBS is extremely common. It’s thought to affect 10–15% of people in the United States. It occurs 2–2.5 times more often in females than in males.

IBS is characterized by a group of symptoms that often occur together with no other obvious cause. Symptoms include:

Stomach flu (viral gastroenteritis)

The stomach flu is a viral infection of your stomach. The most common virus that causes stomach flu is norovirus, which contributes to 19–21 million cases of stomach flu each year.

People at an elevated risk include:

  • infants and young children
  • older adults
  • people with weakened immune systems

Symptoms can include:

  • diarrhea
  • pain, bloating, or cramping in your abdomen
  • nausea and vomiting
  • fever
  • dehydration

Food poisoning

Food poisoning is rarely serious and usually doesn’t last longer than a week. It occurs when you consume food that contains microorganisms such as Salmonella or E. coli.

Symptoms can include:

  • diarrhea
  • stomach pain
  • cramps
  • nausea
  • vomiting
  • fever
  • bloating


Diverticulitis occurs when your diverticula — bulging sacs on the inner wall of your intestines — become inflamed. It’s very common and can cause symptoms such as:

  • abdominal pain, which is often severe and begins suddenly
  • bloating
  • diarrhea
  • constipation
  • nausea
  • vomiting
  • fever and chills

Doctors are not exactly sure what causes diverticulitis, but genetics and lifestyle factors, such as smoking and eating a low fiber diet, may contribute.

Inflammatory bowel disease (IBD)

IBD consists of two conditions: Crohn’s disease and ulcerative colitis. These two conditions cause inflammation in your GI tract that can be severe.

Symptoms can include:

  • persistent diarrhea
  • abdominal pain
  • rectal bleeding
  • weight loss
  • fatigue
  • nausea or vomiting after eating
  • bloating

It’s a good idea to see a doctor if you’re experiencing:

  • bloody diarrhea
  • signs of dehydration such as dizziness or passing only small amounts of urine
  • diarrhea that lasts more than 7 days
  • nausea that keeps coming back or persists for more than a couple of days
  • bloating that lasts longer than 3 weeks or occurs more than 12 times in a month
  • bloating that interferes with daily activities

Doctors use a variety of tests to diagnose GI conditions. Here are some of the tests they may perform:

Food intolerance• elimination of some foods to see whether symptoms improve (elimination diet)
• blood tests
breath test for lactose intolerance
Celiac disease • blood tests
• intestinal biopsy
IBSno definitive test, but a doctor will use tests to rule out other conditions
Stomach flu• based on your symptoms
stool test
Food poisoning• based on your symptoms
• stool test
Diverticulitis • blood tests
• stool test
• imaging such as CT scans, MRI, or ultrasound
IBDendoscopy for Crohn’s disease
• colonoscopy for ulcerative colitis
• imaging such as contrast X-rays, CT scans, or MRI

Here are some treatment options for bloating, nausea, and diarrhea.

Home remedies

Home remedies include:

Food intoleranceavoiding triggering foods
Eating too much fiberreducing fiber or fiber supplement intake
Celiac diseaseavoiding gluten
IBS• avoiding trigger foods
• drinking plenty of fluids
• getting enough sleep
• exercising regularly
Stomach flu• getting plenty of rest
• drinking plenty of fluids
• eating easy-to-digest foods such as soup and plain rice
Food poisoning• staying hydrated
• getting plenty of rest
Diverticulitis• eating high fiber foods or taking a fiber supplement
• taking probiotics
• trying a liquid diet to rest your colon
IBD• eating small meals
• drinking plenty of liquids
• limiting dairy or other foods that cause gas

Medical treatment

Medical options include:

Condition Treatment
Food intolerancelactase pills to break down lactose
IBS• anti-diarrheal medications
anticholinergic medications
tricyclic antidepressants
selective serotonin reuptake inhibitors
• pain medications
Stomach fluanti-vomiting medications
Food poisoningover-the-counter medications such as loperamide (Imodium A-D) or bismuth subsalicylate (Pepto-Bismol)
Diverticulitis• antibiotics
nonsteroidal anti-inflammatory drugs
acetaminophen (Tylenol) or antispasmodic medications
Surgery • 5-aminosalicylic acids
• surgery to remove parts of your GI tract

Nausea, bloating, and diarrhea are all common GI symptoms. They have many potential causes, which range from eating too much fiber to potentially serious diseases such as IBD.

It’s a good idea to speak with a doctor if you have persistent or severe symptoms that are causing you distress or affecting your daily life.