An upset stomach can cause symptoms similar to those of Crohn's disease, which is a form of inflammatory bowel disease (IBD). Although persistent gastrointestinal symptoms may indicate an IBD, such as Crohn's disease, there are numerous other possible causes to consider.

The symptoms of an upset stomach often occur after eating a big meal or drinking too many caffeinated or carbonated beverages.

In this article, we discuss the different causes of an upset stomach, how to treat them, and how to distinguish Crohn's disease from other possible causes.

I woman sat on her bed feeling ill with either a Sour stomach or crohn'sShare on Pinterest
A person with an upset stomach may experience discomfort in the upper abdomen.

An upset stomach refers to a group of symptoms that affect the gastrointestinal (GI) system.

The symptoms of an upset stomach include:

  • discomfort, pain, or a burning sensation in the upper abdomen
  • feeling uncomfortably full during or shortly after a meal
  • growling or gurgling sounds coming from the stomach
  • excess gas that causes bloating or burping
  • nausea

People may have an upset stomach for numerous reasons. Although diseases and infections in the GI tract can cause uncomfortable digestive symptoms, most upset stomachs occur as a result of poor eating habits that lead to indigestion.

Indigestion

The term indigestion broadly refers to the symptoms of an upset stomach, such as bloating and discomfort, after eating a meal.

The symptoms of indigestion occur when the lining of the stomach becomes irritated or inflamed, which can happen if people overeat or eat too quickly.

Consuming too many of the following foods or beverages can also irritate the stomach lining and lead to indigestion:

  • high fat or greasy foods
  • spicy foods
  • alcohol
  • caffeine
  • carbonated beverages

Stress or anxiety

Stress or anxiety can also cause GI symptoms. The GI tract has a nervous system of its own called the enteric nervous system.

The enteric nervous system contains about 200–600 million neurons in the walls of the GI tract. These neurons help control digestive function.

The nerves in the GI tract respond to stress hormones in the same way as nerves in the brain and other parts of the body.

When the brain perceives danger, it signals to the adrenal glands to release stress hormones, such as epinephrine, norepinephrine, and cortisol.

These hormones have several physical effects on the body, including:

  • slowing down digestive organs and restricting their blood supply
  • increasing blood flow to the muscles, brain, heart, and lungs
  • increasing heart rate, breathing rate, and blood pressure
  • dilating the pupils to improve vision
  • suppressing the immune system
  • increasing metabolism

People who regularly have high levels of stress may experience the physical effects of stress hormones. According to the American Psychological Association, stress increases a person's sensitivity to stomach pain, bloating, and nausea. Severe stress can even induce vomiting in some people.

Anxiety is a response to stress, and it refers to a sense of excessive worry, fear, or unease. People who have anxiety can experience a wide range of psychological and physical symptoms, including GI symptoms. These symptoms include:

Read more about the causes and treatment of a nervous stomach here.

Medications

Certain medications can also irritate the lining of the stomach. These include:

Medical conditions

IBD, the types of which include ulcerative colitis and Crohn's disease, can cause unpleasant GI symptoms.

However, people can also develop these symptoms as a result of gastroenteritis, which is inflammation of the intestines due to a viral, bacterial, or parasitic infection.

Other medical conditions that can cause indigestion include:

Crohn's disease is a chronic inflammatory condition that damages parts of the GI tract. Crohn's disease can sometimes affect the stomach, but it usually occurs in the part of the small intestine closest to the large intestine.

People who have Crohn's disease may experience an upset stomach and indigestion, along with other GI symptoms, such as:

  • diarrhea
  • constipation
  • cramps or pain in the abdomen
  • fatigue
  • loss of appetite
  • unintentional weight loss
  • joint pain
  • anemia

Crohn's disease causes nonspecific symptoms for which many other medical conditions could be responsible. As a result, it can sometimes be difficult to distinguish between Crohn's disease and other causes of an upset stomach.

People who frequently experience indigestion should rule out other causes before concluding that they have Crohn's. If people cannot determine a cause, they should speak with a doctor.

A doctor can diagnose the cause of an upset stomach by asking about a person's symptoms, as well as their medical and family histories. They may also perform a physical examination to evaluate a person's overall health and look for signs of GI problems.

During a physical examination, a doctor will measure a person's heart rate, blood pressure, and body weight. They may also press on the person's stomach to check for signs of bloating, pain, or abnormal masses under the skin.

If a doctor thinks that a person may have a GI disease, such as Crohn's disease, they will be likely to order laboratory tests to identify the person's underlying condition.

Laboratory tests that a doctor can use to help diagnose Crohn's disease include:

An upset stomach often clears up without much medical intervention, and it does not usually require a trip to the doctor's office.

People who frequently experience an upset stomach may find it helpful to track their food and beverage intake and their symptoms.

Keeping a record of these may allow a person to identify specific foods and drinks that upset their stomach so they can avoid them in the future.

Other ways to ease an upset stomach include:

  • drinking clear liquids, such as water, decaffeinated tea, and broth
  • eating bland foods that will not upset the stomach, such as white rice, applesauce, and boiled potatoes
  • avoiding food that may upset the GI tract, such as spicy foods, high fiber foods, and caffeine

People can take over-the-counter (OTC) antacid medications, such as bismuth subsalicylate (Pepto-Bismol), to reduce diarrhea, nausea, and other GI symptoms.

Read about 21 home remedies for an upset stomach here.

In general, people do not need to worry if they occasionally experience symptoms of an upset stomach.

However, chronic, severe, or persistent indigestion, stomach pain, or diarrhea may be due to an underlying medical condition that might require medical treatment.

An upset stomach that occurs alongside one or more of the following symptoms may indicate a more serious problem:

  • persistent fever
  • changes in bowel or urinary habits
  • diarrhea or vomiting that lasts more than a day
  • lightheadedness
  • a rapid heartbeat

The National Institute of Diabetes and Digestive and Kidney Diseases recommend that people speak with a doctor or another healthcare professional if they experience symptoms of indigestion that last longer than 2 weeks.

People should seek medical attention immediately if they have indigestion and any of the following symptoms:

  • bloody vomit or stools
  • frequent vomiting or diarrhea
  • black, tar-like stools
  • unintentional weight loss
  • pain in the chest, jaw, neck, or arms
  • severe pain in the abdomen
  • shortness of breath
  • difficulty or painful swallowing
  • excessive sweating
  • yellowing of the eyes or skin

An upset stomach can have many causes. It does not usually warrant a trip to the emergency room, and in most cases, it does not indicate that a person has Crohn's disease.

Typically, an upset stomach occurs as a result of poor eating habits or other minor medical conditions. Therefore, it is best to rule out other possible causes of an upset stomach before considering Crohn's disease as the culprit.

The symptoms of an upset stomach often improve with rest and OTC antacids, such as Pepto-Bismol.

People who have symptoms of an upset stomach that last longer than 1–2 days may want to speak with a doctor. Infections and GI diseases can cause indigestion.

Crohn's disease causes nonspecific GI symptoms, which makes it difficult to diagnose. Doctors may need to run multiple laboratory and imaging tests to rule out other possible conditions before they diagnose Crohn's disease.