What are the key differences between IBS and IBD. How are these digestive disorders diagnosed. What symptoms characterize IBS and IBD. What treatment options are available for IBS and IBD. How do antibody blood tests help diagnose IBS.

Understanding Inflammatory Bowel Disease (IBD)

Inflammatory bowel disease (IBD) is a chronic condition characterized by inflammation and ulceration in the gastrointestinal tract. This disorder occurs when the immune system mistakenly attacks the cells of the bowels, leading to various symptoms and complications.

There are two main types of IBD:

• Ulcerative colitis: Inflammation primarily affecting the large intestine and rectum
• Crohn’s disease: Inflammation that can occur anywhere along the digestive tract

Common Symptoms of IBD

While IBD shares some symptoms with irritable bowel syndrome (IBS), it also presents unique manifestations. Common symptoms of IBD include:

• Diarrhea
• Abdominal pain and cramping
• Rectal bleeding
• Joint pain
• Eye irritation
• Skin rashes
• Fever and fatigue
• Unintended weight loss

Can IBD be cured? Currently, there is no known cure for IBD. However, various immunosuppressant medications can help manage symptoms and reduce inflammation in affected individuals.

Diagnosing Inflammatory Bowel Disease

Diagnosing IBD involves a comprehensive approach, including:

1. Stool tests
2. Blood tests
3. Endoscopic procedures (e.g., colonoscopy)

These diagnostic tools help healthcare providers determine the location and extent of inflammation in the gastrointestinal tract, enabling them to differentiate between Crohn’s disease and ulcerative colitis.

Exploring Irritable Bowel Syndrome (IBS)

Irritable bowel syndrome is a functional gastrointestinal disorder affecting millions of Americans. Unlike IBD, IBS does not cause lasting harm to the bowels or increase cancer risk. However, it can significantly impact a person’s quality of life.

Types of IBS

IBS is classified into three main types based on predominant symptoms:

• IBS-D: Diarrhea-predominant
• IBS-C: Constipation-predominant
• IBS-M: Mixed-type (alternating diarrhea and constipation)

Common Symptoms of IBS

The primary symptoms of IBS include:

• Persistent abdominal pain
• Cramping
• Gas and bloating
• Changes in bowel habits (diarrhea, constipation, or both)

How prevalent is IBS? Nearly 40 million Americans suffer from irritable bowel syndrome, making it a common digestive disorder.

The Link Between Food Poisoning and IBS

Interestingly, food poisoning is the leading known cause of IBS, accounting for at least 60% of all diarrheal IBS cases. This connection involves a toxin called Cytolethal Distending Toxin B (CdtB), which is released by common food poisoning bacteria such as Shigella, Campylobacter, Salmonella, and E. coli.

The Immune Response and IBS Development

When CdtB enters the body, the immune system produces antibodies to fight it. However, CdtB resembles vinculin, a protein crucial for healthy gut function. This similarity can lead to an autoimmune response where the body produces anti-vinculin antibodies, resulting in gut nerve damage and disruption of the gut microbiome.

How does this immune response lead to IBS? The production of anti-vinculin antibodies causes improper functioning of the Interstitial Cells of Cajal (ICC) and Migrating Motor Complexes (MMC), ultimately disrupting the gut microbiome and leading to IBS symptoms.

Diagnosing Irritable Bowel Syndrome

Traditionally, IBS was diagnosed through exclusion, meaning other conditions, especially IBD, had to be ruled out first. However, recent advancements have led to more direct diagnostic methods.

Antibody Blood Tests for IBS Diagnosis

A simple, doctor-ordered antibody blood test can now accurately diagnose IBS. This test measures the levels of two specific antibodies:

• Anti-CdtB
• Anti-vinculin

These antibodies are known to be elevated in the blood of most patients experiencing IBS with diarrheal symptoms. If either antibody is elevated, a confident IBS diagnosis can be made.

How accurate are these antibody tests? While specific accuracy rates may vary, these tests have shown promising results in diagnosing IBS, particularly in cases with diarrheal symptoms.

Treatment Approaches for IBD and IBS

While both IBD and IBS can significantly impact a person’s quality of life, their treatment approaches differ due to the underlying mechanisms of each condition.

Managing Inflammatory Bowel Disease

Treatment for IBD typically focuses on reducing inflammation and managing symptoms. Common approaches include:

• Immunosuppressant medications
• Anti-inflammatory drugs
• Biologics
• Dietary modifications
• Surgery (in severe cases)

The goal of IBD treatment is to induce and maintain remission, prevent complications, and improve the patient’s quality of life.

Treating Irritable Bowel Syndrome

IBS treatment is primarily aimed at symptom management and may include:

• Dietary changes (e.g., low FODMAP diet)
• Stress reduction techniques
• Probiotics
• Antispasmodic medications
• Antidepressants (for pain management)
• Cognitive-behavioral therapy

How effective are these treatments for IBS? While there is no one-size-fits-all approach, many patients find significant relief through a combination of lifestyle changes and targeted therapies.

The Role of Diet in Managing IBD and IBS

Diet plays a crucial role in managing both IBD and IBS, although the specific dietary recommendations may differ for each condition.

Dietary Considerations for IBD

For individuals with IBD, dietary management often focuses on:

• Identifying and avoiding trigger foods
• Ensuring adequate nutrient intake
• Managing symptoms during flare-ups
• Reducing inflammation through anti-inflammatory foods

Some patients with IBD may benefit from specific diets such as the Specific Carbohydrate Diet (SCD) or the Mediterranean diet, although more research is needed to establish their efficacy.

Dietary Strategies for IBS

Dietary management for IBS often involves:

• Following a low FODMAP diet
• Identifying individual food triggers
• Maintaining a regular meal schedule
• Staying hydrated
• Limiting caffeine and alcohol intake

Can dietary changes alone manage IBS symptoms? While diet plays a significant role in symptom management, many patients find that a combination of dietary modifications and other treatments yields the best results.

The Psychological Impact of IBD and IBS

Both IBD and IBS can have significant psychological effects on those affected. Understanding and addressing these impacts is crucial for comprehensive patient care.

Mental Health Considerations in IBD

Individuals with IBD may experience:

• Anxiety about disease progression
• Depression related to chronic symptoms
• Social isolation due to symptoms
• Stress about medical procedures and treatments

How does psychological well-being affect IBD management? Research suggests that psychological stress can exacerbate IBD symptoms, highlighting the importance of mental health support in overall disease management.

Psychological Aspects of IBS

People with IBS often face:

• Anxiety about symptom flare-ups
• Frustration with dietary restrictions
• Embarrassment about symptoms
• Reduced quality of life due to unpredictable symptoms

Addressing these psychological factors through cognitive-behavioral therapy, stress management techniques, and support groups can significantly improve outcomes for individuals with IBS.

Future Directions in IBD and IBS Research

Ongoing research in the fields of IBD and IBS continues to uncover new insights and potential treatment avenues.

Emerging Therapies for IBD

Current areas of research in IBD include:

• Novel biologics targeting specific inflammatory pathways
• Stem cell therapies for tissue regeneration
• Microbiome manipulation through fecal microbiota transplantation
• Personalized medicine approaches based on genetic profiles

What potential do these emerging therapies hold? While many of these approaches are still in early stages, they offer hope for more targeted and effective treatments for IBD in the future.

Advancements in IBS Understanding and Treatment

Research in IBS is focusing on:

• Further elucidating the gut-brain axis
• Developing new diagnostic biomarkers
• Exploring the role of the microbiome in IBS
• Investigating novel pharmacological treatments

These research directions aim to improve diagnostic accuracy, develop more targeted treatments, and ultimately enhance the quality of life for individuals living with IBS.

In conclusion, while IBD and IBS share some symptomatic similarities, they are distinct conditions with different underlying mechanisms, diagnostic approaches, and treatment strategies. Ongoing research continues to enhance our understanding of these disorders, paving the way for improved patient care and management strategies in the future.

IBS vs. IBD | Take Our Symptoms Quiz for IBS

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Is It Really IBS?

Take a short quiz to find out if an antibody blood test for IBS is recommended for you.

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While irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD) share some symptoms, they are completely different illnesses. 

Inflammatory Bowel Disease (IBD)

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Inflammatory bowel disease (IBD) is a long-term health issue that causes swelling and sores in the gastrointestinal tract.

​

IBD causes your immune system to think that food in the intestine is not supposed to be there. The body then attacks the cells of the bowels, causing inflammation and ulcerations. 

There are two main types of inflammatory bowel disease (IBD): ulcerative colitis and Crohn’s disease. 

Symptoms of IBD, like symptoms of IBS, include diarrhea and abdominal pain; however, in addition to these, IBD symptoms also include rectal bleeding, joint pain, eye irritation, and rashes.  

While there is currently no known cure for IBD, there are various immunosuppressants to help manage the symptoms of IBD.

​

Here is an excellent patient guide to IBD published by the American Gastroenterological Society in Clinical Gastroenterology and Hepatology.

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How Do You Diagnose

Inflammatory Bowel Disease (IBD)?

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There are various ways your doctor might want to test for IBD. Diagnostic procedures might include stool tests, blood tests, and often more invasive endoscopic procedures like a colonoscopy. 

Your doctor will want to know where in your body the inflammation is occurring and will want to get a clear understanding of the state of your gastrointestinal tract. 

There are two types of IBD that can be diagnosed. Crohn’s disease is inflammation or ulceration located throughout the GI tract, and ulcerative colitis is inflammation found in the large bowel or rectum. 

Both types of IBD have their own symptoms that guide your doctor towards the most appropriate tests.

Ulcerative Colitis

• Diarrhea

• Fever & fatigue

• Abdominal pain and cramping

• Blood in your stool

• Reduced appetite

• Unintended weight loss

• Red, swollen eyes

Crohn’s Disease 

• Cramps/belly pain (often in the lower right side)

• Diarrhea

• Weight loss

• Bleeding

• Skin rash

• Arthritis (painful, swollen joints)

• Fatigue

Irritable Bowel Syndrome (IBS)

​

Irritable bowel syndrome, or IBS, is a health issue found in your intestines. It causes persistent abdominal pain, cramping, gas, bloating, and change in stool – some combination of chronic diarrhea and constipation. If you are suffering from these symptoms, you’re not alone. Nearly 40 million Americans suffer from IBS. 

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There are three types of IBS: diarrhea-predominant (IBS-D), constipation-predominant (IBS-C), and mixed-type (IBS-M, where diarrhea and constipation both persist). IBS does not cause lasting harm to the bowels and does not lead to cancer; however, it can severely impair you physically and emotionally. 

​

Food poisoning is the leading known cause of IBS, accounting for at least 60% of all diarrheal IBS cases. The path from food poisoning to IBS has to do with a toxin called Cytolethal Distending Toxin B, or CdtB for short. The most common bacteria that cause food poisoning like Shigella, Campylobacter, Salmonella, and E. coli. release the toxin CdtB into your body. 

When a toxin like CdtB enters your body, your immune system fights back with an antibody – in this case, your body creates anti-CdtB. CdtB looks in some ways like vinculin, a naturally occurring protein in your body that is critical in healthy gut function. Because CdtB and vinculin can look alike, your body can think it needs to fight back against vinculin, at which point it starts producing another antibody, anti-vinculin. 

The production of anti-vinculin is an autoimmune response and leads to gut nerve damage and improper functioning of the Interstitial Cells of Cajal (ICC) and Migrating Motor Complexes (MMC). When these do not function properly, your gut microbiome is disrupted. Your gut microbiome is composed of billions of bacteria in your gut that, when balanced, keep your gut healthy.

This disruption ultimately results in irritable bowel syndrome (IBS).

Here is an excellent patient guide to IBS published by the American Gastroenterological Society​.

View Study

How Do You Diagnose Irritable

Bowel Syndrome (IBS)?

Traditionally, IBS was an exclusionary diagnosis, meaning other diseases – especially IBD – had to be ruled out in order to diagnose IBS. Alternatively, an antibody blood test can diagnose IBS more directly. 

Irritable bowel syndrome can be accurately ruled in with a simple, doctor-ordered antibody blood test.  The test measures the levels of two antibodies, anti-CdtB and anti-vinculin, known to be elevated in the blood of the majority of patients experiencing IBS with diarrheal symptoms. If either antibody is elevated, a confident IBS diagnosis can be made.  

A positive result on the test also indicates that the root cause of your IBS was an instance of food poisoning (gastroenteritis) that has led to a disruption in your gut microbiome. This can guide your healthcare provider to therapies that treat your microbiome, like FDA-approved antibiotics and low-fermentation diets. 

If your antibody blood test result is not positive, your doctor may want to conduct other tests to diagnose your symptoms.

The American College of Gastroenterology’s Clinical Guidelines for the Management of IBS suggest “a positive diagnostic strategy” (ruling in IBS) as compared to “a diagnostic strategy of exclusion” (ruling out other diseases) “…to improve time to initiate appropriate therapy….and to improve cost-effectiveness.”

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What Is ibs-smart?

ibs-smart is the only licensed, patented test that can measure validated biomarkers, anti-CdtB and anti-vinculin,  in your blood that indicate IBS with 96% – 100% positive predictive value. Further, the test is over 90% specific in differentiating IBS from other diarrheal diseases like IBD. While IBS and IBD can co-exist, IBD itself does not lead to the elevation of these antibody biomarkers.

By accurately diagnosing your IBS and identifying the cause (a microbiome disruption caused by an infection), ibs-smart™ can expedite your path to treatment and prevent years of potentially unnecessary procedures like colonoscopies.

You can order ibs-smart without an appointment online through our online prescriber service or download a patient-doctor discussion guide to take to your next doctor’s appointment.

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You can work with a doctor online to order ibs-smart, if it’s right for you.

The online prescriber service includes:

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• A symptoms evaluation by a doctor

• Clear and actionable results emailed directly to you

• Post-test results consultation by phone with a doctor

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Prefer to work with your healthcare provider instead? Download the ibs-smart discussion guide and educational materials here.  

Post-Infectious IBS

A significant volume of research shows a clear link between food poisoning

and irritable bowel

syndrome (IBS).

Read More

Diarrhea & IBS

Chronic diarrhea can indicate disorders, such as inflammatory bowel disease (IBD) or irritable bowel syndrome (IBS).

Read More

SIBO & IBS

While what causes SIBO is an excess of bacteria, there are many conditions that can lead to SIBO like irritable bowel syndrome.

Read More

Do I Have Crohn’s disease or IBS? A Quiz to Help Understand Your Symptoms

‍Irritable bowel syndrome (IBS) and Crohn’s disease may share some of the same symptoms, but they are two very different health conditions. Crohn’s disease is one of two conditions under inflammatory bowel disease (IBD), a potentially serious condition that impacts the structure of the bowel.

In contrast, IBS is classified as a functional gastrointestinal disorder, meaning there are changes in the function of the GI tract that cause symptoms, but you won’t see structural changes or abnormalities on a blood test.

Anytime you notice changes in your digestive health, visiting a healthcare provider is essential. Both IBS and Crohn’s disease impact the gut, but the diagnosis and treatment of each condition vary. 

Understanding the key differences between IBS and Crohn’s disease can help you get the proper support and care for your needs.

IBS vs Crohn’s Disease

At first glance, it may be hard to differentiate IBS from Crohn’s disease. Aside from both being gastrointestinal disorders, they can share many of the same symptoms. Both conditions can also significantly impact your quality of life. 

The most noticeable difference between the two disorders is that while IBS is a functional disorder, Crohn’s disease is a chronic inflammatory disease related to autoimmunity. An autoimmune disease means the immune system mistakes healthy tissue for a foreign invader, so immune cells attack tissues and can cause long-term damage. 

Having IBS doesn’t mean you’ll develop Crohn’s or vice versa—they are two separate disorders. Let’s take a closer look at each in more detail.

What Is Crohn’s Disease?

Crohn’s disease is a chronic condition that causes inflammation along the GI tract anywhere from the mouth to the anus. The exact cause isn’t known, but it’s likely a combination of genetics, immune dysfunction, and environmental exposures.

People with Crohn’s may experience episodes of remission and relapse, with cases ranging from mild to severe. Over time inflammation in the bowel wall can cause fistulas, bowel obstructions, strictures, and eventually surgery.

Symptoms of Crohn’s Disease

Symptoms of Crohn’s disease can include:

• Abdominal pain, especially in the right lower belly.
• Weight loss.
• Diarrhea.
• Bleeding or mucus in stools.
• Fatigue.
• Gas and bloating.
• Anemia.

Crohn’s disease can also include extraintestinal symptoms, which occur outside of the digestive system. These include eye inflammation, swelling and sores in the mouth, and arthritis (painful, swollen joints).  

Diagnosis and Treatment of Crohn’s Disease

If you have symptoms of IBD or Crohn’s, your doctor will likely recommend a comprehensive work-up, including blood tests, stool tests, endoscopy, and colonoscopy, to confirm and examine any structural changes or inflammation in the intestines. 

Fecal calprotectin, a test specifically used for IBD, and inflammatory markers like C-reactive protein (CRP) or Erythrocyte sedimentation rate (ESR)  are often used to differentiate between IBS and Crohn’s and monitor disease activity.

‍Treatment for Crohn’s depends on the severity and progression of the disease but will usually include a combination of medications, including steroids or biologics to suppress the immune system, plus lifestyle changes. 

Diet is essential to support the health of the digestive tract and address inflammation. Certain foods or textures can trigger symptoms or irritate the lining of the intestines, especially during a flare. Undernutrition is a concern for people with Crohn’s.  

Nourish offers one-on-one counseling for people with Crohn’s and accepts the most popular insurance carriers. If you need support, consider booking a virtual appointment with a registered dietitian.

What is IBS?

Irritable bowel syndrome is considered a gut-brain disorder because the brain and nervous system can affect the health and function of the digestive tract.

While not as severe as Crohn’s disease in terms of inflammation, IBS can still cause considerable discomfort. It’s also extremely common, affecting 5 to 10% of the population worldwide.

There are four categories of IBS, according to the American College of Gastroenterology (ACG):

• IBS-C: Constipation predominant.
• IBS-D: Diarrhea predominant.
• IBS-M: Alternating constipation and diarrhea.
• IBS-U: Meets the criteria for IBS, but stool consistency (loose or hard) doesn’t fall into the expected pattern of the categories.

Women are more likely to be diagnosed with IBS. Prevalence also appears to decrease with age, with 25% fewer people diagnosed after age 50. There’s no single cause of IBS, but likely related to factors such as alterations in gut motility, brain-gut interactions, stress, history of food poisoning, and genetic predisposition. 

IBS may have a relationship to alterations in the gut immune system, meaning it involves the immune cells and causes inflammation, but it’s not an autoimmune process that causes tissue damage, as seen with Crohn’s. It often appears with other health conditions, especially anxiety and depression. 

Symptoms of IBS

‍Symptoms of IBS vary from mild to severe and can include:

• Abdominal pain.
• Constipation, diarrhea, or both.
• Bloating and gas.
• Nausea.
• Changes in appetite.

Diagnosis and Treatment of IBS

Diagnosis for IBS includes reviewing medical history and an exam to check for underlying conditions like IBD or celiac disease.  

The Rome IV criteria, a set of criteria that people with IBS must meet for diagnosis, state that people with IBS should report recurrent abdominal pain at least once a week in the last three months associated with at least 2 of the following:

• Pain related to bowel movements.
• Change in frequency of stool.
• Change in stool form (appearance) of stool.

Like Crohn’s, treatment for IBS depends on severity. Lifestyle changes addressing diet, sleep, and stress are often enough to manage IBS symptoms. Medications may help with severe symptoms, but immunosuppressants aren’t necessary. 

Diet can play a significant role in addressing and managing IBS. Studies suggest that working with a registered dietitian to assess for gaps in nutrition and develop and guide people with IBS through elimination diets can significantly help with quality of life and lowering symptoms.

One of the most common patterns used for IBS is the low FODMAP diet. FODMAP stands for fermentable oligo-, di-, mono-saccharides, and polyols, short-chain carbohydrates found in many foods. Some people find these carbohydrates difficult to digest, causing gas, bloating, and other symptoms.

The low FODMAP is not meant to be a long-term diet because it can be overly restrictive. Working with a dietitian can help you customize the elimination and reintroduction phases to meet your needs.

8 Questions to Help Identify If You Have Crohn’s Disease or IBS

You can use the following questions to identify patterns and guide your conversation with your doctor. These results are only a starting point and not a replacement for medical advice.

Consider the following questions:

1. Have you experienced ongoing abdominal pain and discomfort at least once a week over the past three months?
2. Do you alternate between constipation and diarrhea?
3. Do your symptoms improve after having a bowel movement?
4. Do you experience anxiety or depression?
5. Are you prone to developing mouth sores or ulcers? 
6. Do you experience fatigue or weakness?
7. Do you have unexpected weight loss?
8. Do you experience rectal bleeding or blood in your stools?

Interpreting Your Results

If you answered “yes” to questions one through four, IBS could be a possibility to discuss with your doctor.