IBS vs. IBD: A Closer Look at Bowel Disorders

When grappling with persistent gut issues, you might hear two acronyms: IBS and IBD. Though their letters look strikingly similar, and both bring a host of unpleasant digestive symptoms, they are fundamentally different conditions. Although both can make you miserable, one is a serious threat to your health, and can increase risks of colon cancer, hospitalization, and surgery.

What is Irritable Bowel Syndrome (IBS)?

Irritable Bowel Syndrome (IBS) causes symptoms like abdominal pain or cramping, bloating, gas, and changes in bowel habits – such as diarrhea, constipation, or both. However, when doctors look inside with scopes, scans, or labs, there's no visible inflammation, ulcers, or physical damage. Blood work is often normal.

The reason for this is that it is a "disorder of gut-brain interaction.” There are as many nerves in the digestive tract as the rest of the body put together. These nerves communicate with the brain, but also affect how the gut communicates with itself. These nerves can become disordered. This disrupts your gut’s normal functioning – it might squeeze too hard, too soft, too fast, or too slow. These disordered nerves can also send the wrong message to your brain, sending signals of injury or pain when they should not. 

IBS symptoms like abdominal pain, cramping, relentless bloating, excessive gas, and unpredictable shifts in bowel habits (from chronic diarrhea to stubborn constipation, or a frustrating mix of both) stem from how your gut works, not from a problem with the stomach or intestines themselves. 

What is Inflammatory Bowel Disease (IBD)?

In contrast, Inflammatory Bowel Disease (IBD) is a condition in which the body’s immune system attacks itself at the level of the digestive tract. The two most common sub-types of IBD are Crohn's disease and Ulcerative Colitis. This leads to visible, destructive inflammation within the digestive tract, much like a chronic, internal wound.

Symptoms are often more severe and can include persistent, sometimes bloody diarrhea, debilitating abdominal pain, crushing fatigue, and alarming weight loss. Unlike IBS, IBD can lead to serious complications such as painful ulcers, dangerous bowel obstructions, and a significantly increased risk of colorectal cancer.

Paths to Diagnosis and Treatment

IBS Diagnosis

An IBS diagnosis primarily relies on your symptom patterns and carefully ruling out other conditions using established clinical criteria. Although we can’t find something “wrong” with our current lab tests or endoscopy, IBS causes very specific and reproducible patterns that GI specialists can observe in order to make the diagnosis.  A good, honest conversation about your symptoms with your GI provider is the key.

IBD Diagnosis

IBD cannot be diagnosed by symptoms alone.  A correct diagnosis requires a colonoscopy with biopsies of the intestines, and possibly an upper endoscopy as well.  Tests including blood work (looking for inflammatory markers), stool tests (like fecal calprotectin), scans like an MRI or CT scan can support the diagnosis, and help your doctors understand its severity.  But the scope is the most important tool to make the diagnosis.

Similarly, treatments aim for different goals.

IBS Treatment

Treatment for IBS centers on managing symptoms and identifying individual triggers. This often involves tailored dietary changes (like the low-FODMAP diet), identifying external triggers like stress, and using medications to target the abnormally functioning nerves involved in the gut-brain signals.

IBD Treatment

IBD treatment focuses on controlling and reducing inflammation in the gut in order to achieve healing of inflamed tissues.  Although improving diet and sleep can help with symptoms, the inflammation cannot be treated with diet alone. Treatments include anti-inflammatory medications and specially designed medications that work at very specific targets in the immune system. For severe or unresponsive cases, surgery can be helpful in order to restore health.

Can You Have Both IBS and IBD?

Yes, you absolutely can. It's a challenging reality that many individuals with diagnosed IBD also experience IBS-like symptoms, even when their IBD is in remission. This overlap can make both diagnosis and effective treatment more complex.

When to See a Doctor

If you're experiencing persistent digestive symptoms that disrupt your life, it's crucial to consult a health care professional. Do not try to self-diagnose. Seek immediate medical attention if you experience alarm symptoms such as:

• Blood in your stool
• Severe and unrelenting abdominal pain
• Unexplained or significant weight loss
• Persistent fever accompanying digestive issues
• Abdominal pain or diarrhea that wake you from sleep

Understanding the distinct natures of IBS and IBD is the first step toward getting the right diagnosis and finding effective strategies to reclaim your digestive health and quality of life.