What Is Irritable Bowel Syndrome (IBS)?

Irritable bowel syndrome (IBS) is a common condition that affects the gastrointestinal (GI) system. Symptoms include abdominal pain and cramping, bloating, diarrhea, and/or constipation. Women and people younger than age 50 are more likely to develop IBS.

This article discusses the diagnosis and types of IBS, along with its symptoms, risk factors, triggers, and treatments.

What Are the Symptoms of IBS?

As IBS affects the GI tract, the main symptoms are felt in the abdominal area and related to bowel movements. Common IBS symptoms include:

• Pain in the abdomen
• Abdominal bloating
• Diarrhea
• Constipation
• Gas
• A feeling of incomplete bowel movements
• Whitish mucus in the stool

IBS Symptoms in Women

Women with IBS have reported more symptoms than men, including fatigue, insomnia, backache, depression, anxiety, and lower quality of life. More women than men seem to have the subtype of IBS with constipation.

People who menstruate tend to experience more IBS symptoms during their menstrual period. There also seems to be an overlap of IBS symptoms and symptoms of endometriosis, warranting further investigation if you have been diagnosed with IBS but are still experiencing GI or gynecological-related symptoms.

Types of IBS

Though IBS encompasses a group of symptoms, there are three main subtypes that are defined based on patterns of bowel movements. With IBS, many people have days of normal bowel movements, while on other days, they have abnormal bowel movements.

The subtypes are:

• IBS with constipation (IBS-C): On days with abnormal bowel movements, more than one-fourth of your stools are hard or lumpy, and less than one-fourth are loose or watery.
• IBS with diarrhea (IBS-D): On days with abnormal bowel movements, more than one-fourth of your stools are loose or watery and less than one-fourth of your stools are hard and lumpy.
• IBS with mixed bowel habits (IBS-M): On days with abnormal bowel movements, more than one-fourth of your stools are loose or watery and more than one-fourth of your stools are hard and lumpy.

Some people who mainly experience one subtype of IBS may later change to a different subtype. Knowing the subtype of IBS you have can help your healthcare provider better treat your IBS.

What Are the Causes and Risk Factors for IBS?

Irritable bowel syndrome is a functional gastrointestinal disorder related to how your brain and gut work together.

There is two-way communication between the central nervous system (brain and spinal cord) and the enteric nervous system (in the gut). This links the gut microbiota (a wide variety of bacteria, viruses, fungi, and other microorganisms) and the brain. This bidirectional signaling pathway is called the gut-brain axis.

When this signaling is disordered, your gut is more sensitive and you may feel symptoms such as bloating and abdominal pain. The muscle contractions in your gut may also be affected, which can lead to constipation or diarrhea.

Experts aren’t sure exactly what causes IBS. They think a combination of risk factors may be to blame. Below are factors that may increase your risk of developing IBS:

• Food intolerances or sensitivities
• Small intestinal bacterial overgrowth (SIBO) (a change or increase in the number or type of bacteria in your small intestine)
• Bacterial infections in your GI tract
• Stressful or difficult early life events
• Certain mental health disorders, such as anxiety, depression, and somatic symptom disorder
• Certain genetics

What Triggers IBS?

IBS triggers are different for each person with IBS. Not everyone will react to each item on this list. However, there are some common triggers that seem to bring on symptoms in many people with IBS. These include:

• Foods high in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs), which are carbohydrates such as fructose, lactose, and sugar alcohols that are poorly absorbed in the small intestine
• Caffeine
• Alcohol
• Fatty or spicy foods
• Stress
• Certain medications, such as non-steroidal anti-inflammatory drugs (NSAIDs)
  

How to Diagnose IBS

To diagnose IBS, a healthcare provider will first review your symptoms as well as your family and medical histories. They will perform a physical exam usually including checking for abdominal tenderness, pain, and bloating, as well as listening to sounds within your abdomen.

Your healthcare provider might also order some tests to help rule out other potential causes for your symptoms. These tests may include:

• Blood tests
• Stool test
• Colonoscopy
• Endoscopy
• Hydrogen breath test

Treatment for IBS

Treatment for IBS will vary based on your individual symptoms. You may have to try different treatments to see what works best for you. Your healthcare provider can help guide you in choosing the best treatment plan for you.

Below are medication, dietary supplement, and mental health treatment options for IBS.

Medication treatment options may include:

• Loperamide
• Viberzi (eluxadoline)
• Lotronex (alosetron) (prescribed only to women and with special warnings and precautions)
• Amitiza (lubiprostone)
• Linzess (linaclotide)
• Trulance (plecanatide)
• Antibiotics
• Antispasmodics
• Antidepressants
• Laxatives

Dietary supplement treatment options may include:

• Coated peppermint oil capsules
• Fiber supplements
• Probiotics

Mental health treatment options may include:

• Cognitive behavioral therapy (CBT)
• Gut-directed hypnotherapy
• Relaxation training

Lifestyle and Diet for IBS

Another big aspect of treating and managing IBS is lifestyle and diet. Your healthcare provider may refer you to a registered dietitian to help guide you in identifying your individual diet triggers for IBS.

Lifestyle and diet treatment options may include:

• Eating a high-fiber diet
• Avoiding gluten
• Following a low-FODMAP diet
• Increasing physical activity
• Reducing and managing stress
• Getting enough sleep

Complications of IBS

Unlike some other gastrointestinal disorders, there is usually no inflammation found in the GI tract with IBS. However, irregular bowel movements may increase the risk of hemorrhoids or impacted bowels. Chronic diarrhea may increase the risk of dehydration.

Long-term dietary restrictions may lead to nutritional deficiencies or other nutritional concerns. Working with a registered dietitian who specializes in IBS can help ensure you are meeting all your nutritional needs.

Due to the frequency and severity of symptoms in people with moderate to severe IBS, there may be a decrease in quality of life. For example, irregular bowel movements and abdominal pain may lead people to avoid, cancel, or leave early from social engagements and cause problems at work, including increased missed days of work.

People with IBS have an increased number of healthcare visits, diagnostic tests, and surgeries. They also tend to have more anxiety and depression than those without IBS.

Is There a Cure for IBS?

Currently, there is no cure for IBS. IBS is a chronic (long-term) condition that can affect people for their whole lives. However, symptoms are often manageable and can improve with a proper treatment plan, including diet and lifestyle changes.

Each person’s journey with IBS is different. Some people experience symptoms only a few days a month, while others might have symptoms daily for weeks or months. Working with a healthcare provider to develop an effective treatment plan can help decrease symptoms and improve quality of life.

When to See a Healthcare Provider for IBS

People with IBS will often experience days with constipation and/or diarrhea. However, if symptoms are continuous and include severe abdominal pain, it is a good idea to make an appointment with a healthcare provider, such as a gastroenterologist. 

If you have been following a prescribed treatment plan for at least three months and have not seen any improvement, schedule an appointment to reevaluate your treatment plan. Additionally, if you experience new symptoms not typical of IBS, contact your healthcare provider immediately:

• Fever (102 degrees or more and lasting longer than three days)
• Blood in the stool
• Lack of appetite (not explained by an unwillingness to consume trigger foods)
• Unexplained weight loss
• Extreme fatigue
• Vomiting