Irritable Bowel Syndrome Symptoms, Treatments, and Causes

• IBS is a common gut health condition where the digestive tract is more sensitive to normal digestive functions, such as eating food or passing stool.
• Symptoms of IBS include abdominal pain, bloating, and changes in bowel movements, including constipation, diarrhea, or a mix of the two. 
• IBS is typically diagnosed based on its symptoms, and treatment focuses on reducing the frequency of IBS flares and the severity of symptoms. 

Irritable bowel syndrome (IBS) is a chronic condition that impacts the digestive tract. It’s a common condition affecting about 12% of the US population. Symptoms of IBS can vary, depending on the type of IBS. Even more, other gut conditions, such as inflammatory bowel disease (IBD), may have similar symptoms, making it difficult to diagnose IBS.

Continue reading to learn how to spot the IBS symptoms, when to see a healthcare provider about these symptoms, and effective treatments for those who experience symptoms. 

Irritable bowel syndrome (IBS) is a chronic condition that impacts someone’s digestion and their overall quality of life. It’s considered a disorder of gut-brain interaction (DGBI), meaning symptoms stem from issues with how the gut and brain work.

The gut and brain are connected via the central nervous system. The brain speaks bidirectionally with our gut via our thoughts and emotions impacting gastric functions such as motility and secretions. That communication is why we have sayings like ​“he gives me butterflies” or ​“my stomach is in knots.” Our emotions and mental health can impact what happens to our gut and vice versa. 

In people with IBS, the gut-brain connection works differently, resulting in a sensitive gut and inefficient regulation of muscle contractions in the GI tract. These two changes mean the gut is more sensitive and reactive to normal functions like digesting food or having a bowel movement. Collectively, the symptoms from these changes in the digestive system are what we call IBS.

How Common Is IBS?

According to the National Institute of Digestive and Kidney Diseases, about 12% of the US population has IBS. However, IBS is underdiagnosed, meaning more people may have this condition than we know.

IBS symptoms vary, though the most frequently reported symptoms often include abdominal pain, bloating, and changes in bowel function. It’s important to note that these main symptoms often come and go. When symptoms are present they are referred to as ​“flares.” 

Abdominal Pain

Abdominal discomfort or pain is one of the most common symptoms of IBS. It can occur without a trigger or after eating a large meal. It’s actually one of the diagnostic criteria for IBS, making it a symptom everyone with this condition experiences at one point or another. Abdominal pain feels different for everyone, ranging from a sharp and stabbing sensation for some to a dull and cramping sensation for others.

Bloating

IBS can also make the stomach feel uncomfortably full, leading to bloating. This bloating is often due to incomplete emptying of the bowels leading to a persistent feeling of stool in the GI tract after a bowel movement. Many people describe the bloating sensation as a ​“balloon inflating in their stomach,” as it makes their abdomen hard, distended, and painfully full of gas.

Changes in Bowel Movements

IBS causes changes in bowel movements, which most often take the form of diarrhea (too frequent bowel movements) or constipation (infrequent bowel movements). IBS may also cause other changes to bowel movements, such as loose stools, feeling as if a bowel movement is unfinished, or trouble controlling when bowel movements start, which may lead to stool leaking before getting to the bathroom or to straining on the toilet for a long time.

Other Symptoms

While abdominal pain, bloating, and bowel movement changes are the hallmark symptoms of IBS, it’s not uncommon to experience additional symptoms such as:

• Passing gas more often than usual
• Mucus in stool
• Fatigue
• Backache
• Feeling nauseous

As a result, IBS may result in emotional discomfort or stress from digestive changes or worrying about having to find a bathroom quickly. Up to a third of people with IBS also have anxiety or depression, and even more people with IBS report psychosocial impacts from IBS. 

Severe Symptoms

In rare cases, IBS may cause abdominal pain that is so severe that it prevents you from going out or completing daily activities. However, it doesn’t typically cause other serious symptoms, such as unexplained weight loss, rectal bleeding, or excessive vomiting. If you are experiencing severe digestive symptoms or any of the aforementioned serious symptoms, seek emergency medical care. 

Irritable Bowel Syndrome (IBS) is categorized into three primary types based on a person’s predominant bowel patterns. Identifying the specific subtype is essential, as clinical treatments are tailored to each unique symptom profile. 

IBS With Constipation (IBS‑C) Symptoms

If someone usually has constipation alongside other symptoms, they may be diagnosed with IBS‑C. This type of IBS often responds to medication or dietary adjustments, such as increasing fiber intake to regulate the digestive system.

IBS With Diarrhea (IBS‑D) Symptoms

If your predominant symptom is diarrhea you may be diagnosed with IBS‑D. If left untreated, food can pass through the body too quickly, leading to poor nutrient absorption and ultimately malnutrition. Poor absorption may lead to micronutrient deficiencies, such as a vitamin B12 deficiency or anemia.

IBS Mixed (IBS‑M) Symptoms

Sometimes, a person with IBS has bouts of constipation and periods with diarrhea. This is classified as IBS mixed (IBS‑M), and often requires a flexible treatment plan that includes treatment for constipation and diarrhea. 

The cause of IBS is unknown. There may be a genetic component, though lifestyle and environmental factors seem to play a role, too. That said, some people are more likely to receive an IBS diagnosis, including:

• People younger than 50
• Women
• People with a family history of IBS
• Those diagnosed with anxiety, depression, or certain other mental disorders
• Individuals who have experienced trauma in the past, such as physical or emotional abuse
• People with bacterial infections in the digestive tract
• Those who have certain food intolerances or sensitivities, such as lactose intolerance or gluten intolerance
• People who eat a diet high in ultra-processed foods, like pastries, fries, and chips
• Individuals who have celiac disease 

Sometimes, IBS flares up for no obvious reason. Other times, IBS symptoms surface in response to a trigger. These ​‘triggers’ are internal or external stimuli that affect the gut or the mind-gut connection. 

Triggers vary from person to person, but the most common ones are:

• Stress
• Excessive worrying
• Difficult or negative emotions
• Alcohol
• Caffeine
• Artificial sweeteners
• High-fat foods
• Spicy foods
• Chocolate
• Dairy products
• Fermentable oligosaccharides, disaccharides, monosaccharides, and polyols, otherwise known as ​“FODMAPs”

Not all of these triggers apply to everyone who has IBS, and some may be difficult to spot because they are healthy foods for most people. FODMAPs, for example, are a few ​“lettered” subgroups of carbohydrates (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) that digest slowly in the GI tract. Many FODMAPs, such as apples and broccoli, are part of a healthy diet unless they are a personal trigger.

To discover what triggers IBS, someone may want to keep a mental health and food diary where they note what they ate, how they feel, and any IBS symptoms. They can then share this data with a healthcare provider who can help them complete an elimination diet to discover their triggers.

IBS is diagnosed by a healthcare provider, usually a doctor who specializes in gut health, called a gastroenterologist, or a primary care provider with experience in gut health. In an initial appointment, they may ask about symptoms, a your medical history, and if anyone in your family has IBS. They will also perform a focused physical exam.

During this appointment, healthcare providers look for signs of the Rome IV Diagnostic Criteria:

• Abdominal discomfort or belly pain that occurs at least one day a week for three months or longer
• Pain related to at least two of these three:
  • An increase or decrease in bowel movement frequency
  • Defecation
  • A change in stool shape

Usually, IBS is diagnosed without the use of laboratory tests. However, since other conditions have similar symptoms, doctors may order other tests to rule out other conditions. This may include a blood test, stool test, a colonoscopy, and/​or imaging tests. 

Conditions that share symptoms with IBS include:

• Crohn’s disease
• Colorectal cancer, also known as colon cancer
• Ulcerative colitis (UC)
• Liver disease
• Some severe infections
• Abnormal growths in the gastrointestinal tract
• Problems with the pelvic muscles or the spinal cord

There is no cure for IBS, but certain treatments and lifestyle changes can help manage symptoms. Working with a healthcare provider is the best way to create an effective, personalized treatment plan. 

Treatment Options

To treat IBS, a healthcare provider may recommend:

• Medication for diarrhea: For IBS‑D, recommended medications may include loperamide, rifaximin (Xifaxan), and eluxadoline (Viberzi).
• Medication for constipation: Medications like laxatives, lubiprostone (Amitiza), and linaclotide (Linzess) may help with constipation.
• Medications for mental health: Antidepressants and anti-anxiety medications may help reduce symptoms by addressing emotional triggers of IBS.
• Supplements: Peppermint oil capsules, fiber supplements, and some other supplements may help relieve symptoms, but make sure to check with a healthcare provider before starting any supplements.
• Therapy: Because IBS is a gut-brain condition, many people find working with a therapist helps reduce IBS flares.

Living with IBS

Once you’ve identified any trigger foods, you can work with a healthcare provider, such as a registered dietitian, to develop a dietary plan that avoids these foods. Depending on the type of IBS, they may also recommend dietary adjustments like:

• Eat more fiber, which can be found in whole grains, fruits, and vegetables
• Avoid large meals, which may cause abdominal pain or cramps
• Eat more whole foods and fewer ultra-processed foods
• Eat a balanced mix of foods that are good for digestion, such as whole grains, fruits, vegetables, protein sources, seeds, and nuts.

It may also be useful to incorporate lifestyle changes that help with symptoms, such as:

• Exercising regularly
• Addressing any sleep disturbances, such as insomnia or sleep apnea
• Practicing relaxation techniques, like breathwork or yoga, to help manage stress
• Developing good bowel habits, such as finding a daily time to go to the bathroom or improving toilet posture 
• Getting enough sleep, which is seven to nine hours for most adults

There is no way to prevent IBS, but habits that support mental and physical health, like managing stress, exercising regularly, and getting high-quality sleep, can help manage the frequency and severity of symptoms should they arise.