There is no way a person can tell for sure that they have irritable bowel syndrome (IBS), as there is no distinct symptom or test that can confirm a diagnosis. Instead, doctors diagnose IBS by ruling out other conditions.

IBS is a collection of symptoms that include abdominal pain, diarrhea, and constipation. However, these symptoms can occur for many reasons. Inflammatory bowel disease (IBD), food intolerances, and other conditions can closely resemble IBS.

If a person is concerned they might have IBS, they can begin the diagnosis process by contacting a doctor.

In this article, we will discuss IBS symptoms, diagnosis, and treatment options.

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There is no way for a person to be sure they have IBS without seeking a diagnosis from a doctor. This is because IBS is a syndrome, or collection of symptoms, which can vary from person to person. There is no distinctive sign or symptom that reliably indicates IBS.

The main symptoms of IBS are:

  • abdominal pain
  • bloating
  • diarrhea
  • constipation

Some people also have mucus in their stool or a feeling that a bowel movement is incomplete.

Not everyone with IBS will have all of these symptoms. Some may have only diarrhea or only constipation. Others may have both at different times.

IBS can also cause issues with absorbing nutrients from food. This is known as malabsorption. Malabsorption can lead to a range of symptoms, such as unintentional weight loss, tiredness, and nutrient deficiencies.

No, a person cannot test themselves for IBS. There is no specific diagnostic test that can confirm a person has the condition.

Doctors make a diagnosis based on symptoms and medical history and by ruling out other causes with tests a person cannot do at home.

Yes, it is possible to develop IBS suddenly. A common cause for this is an infection in the digestive system, such as a stomach bug. This can lead to a condition known as postinfectious IBS after the infection resolves.

It is also possible for a person to have a chronic or ongoing infection that mimics IBS. A person could have a viral, bacterial, or protozoal infection that comes on suddenly or causes persistent symptoms. Examples include Giardia and Clostridioides difficile.

If a person does develop IBS and has not recently had an infection, there could be other causes. Scientists are still learning about this. However, the following factors may contribute:

  • Alteration in gut flora: The intestines contain many different species of microbe. When a person’s gut flora is healthy, these microbes work together to kill harmful organisms and digest food, among other functions. However, if gut floral becomes imbalanced, this may contribute to IBS. Infection, inflammation, and medications such as antibiotics can harm a person’s gut flora.
  • Gut-brain axis (GBA) alteration: The GBA refers to the connection between the gut and the brain, which connect via nerves. Disturbances in the GBA due to stress, traumatic events, or other factors may contribute to IBS.
  • Motility problems: Motility refers to how food moves through the digestive system. Fast or slow motility may contribute to IBS.
  • Visceral hypersensitivity: This is when the viscera, or intestines, become hypersensitive, allowing someone to feel pain and other sensations that others cannot feel.
  • Immune cell activation: The lining of the intestines contains cells that fight infections, including T cells and mast cells. When the cells detect a threat, they release inflammatory cytokines. Sometimes, this changes how the digestive system works, with lasting effects.

To diagnose IBS, a doctor will first ask about a person’s symptoms. It is important to be specific when describing symptoms.

Next, the doctor may ask whether there is a family history of digestive conditions. They will then carry out a physical examination by pressing the abdomen to check for bloating, swelling, or pain.

A doctor may recommend tests to rule out other health conditions. These could include:

IBS is a complex condition that is not well understood by doctors. Currently, there is no cure.

However, people can gain relief from their symptoms and significant improvements in their quality of life by getting support and treatment. This may involve:

  • Medications: Some medications can help manage the symptoms of IBS. For example, some medications may increase bowel movement frequency, while others may reduce diarrhea. Certain antidepressants or antispasmodics can also reduce abdominal pain.
  • Dietary changes: Many people with IBS have triggers that set off their symptoms. People can work with a dietitian to identify what they might be and avoid them in the future. Learn more about IBS diets here.
  • Psychological therapies: IBS is a physical condition, not a mental illness. However, because the gut and the brain are connected, stress and emotions can affect digestion. People may benefit from relaxation techniques, gut-directed hypnotherapy, or psychotherapy.
  • Treatment for underlying conditions: Sometimes, a person may have underlying conditions causing their symptoms, so doctors may aim to treat those. For example, the antibiotic rifaximin (Xifaxan) may help to treat SIBO.

There is no way to tell for sure whether a person has IBS without consulting a doctor. This is because IBS does not have any specific, distinctive symptoms that set it apart from other conditions. There are also no specific tests that can confirm a person has IBS.

People who are concerned they might have IBS should speak with a doctor. The symptoms of IBS can be similar to other conditions that need prompt treatment, such as an infection or IBD. A doctor can test for these and make a diagnosis.