IBS vs IBD: A Patient’s Guide to Spotting the Differences

Feeling a little constipated or bloated? Is your tummy out of sorts? If your gut troubles persist, heed your gut feeling. You might wonder: Is this IBS? Or could it be IBD? While these acronyms may sound similar, they refer to two distinct gastrointestinal conditions that require different approaches. To complicate matters, some people may have both conditions simultaneously.

Irritable Bowel Syndrome (IBS) and Inflammatory Bowel Disease (IBD) are distinct conditions. They affect your digestive system in different ways and have different approaches to their treatment. Even after, they have very different long-term health implications.

IBS is one of the most frequently reported digestive disorders in the United States, affecting an estimated 25 to 45 million people. IBD, while less common than IBS, still impacts millions. The Centers for Disease Control and Prevention reports that roughly 2.4 to 3.1 million Americans live with an IBD diagnosis. A recent research conducted by a group of international IBD and public health experts shows a sharp global rise in IBD worldwide.

In this article, we’ll break down exactly what IBS and IBD are, how they differ, how they’re diagnosed, and the treatment options available.

The Main Difference: Inflammation vs. No Inflammation

The simplest way to distinguish the two is:

• IBD involves inflammation in the digestive tract.

• IBS does not involve inflammation.

What is Inflammatory Bowel Disease?

IBD is an umbrella term for Crohn’s disease and ulcerative colitis. Both of these conditions cause chronic inflammation in the digestive tract. The major distinguisher of this condition is that it is triggered by a faulty immune system that attacks the body’s tissues. IBD is chronic, and it comes in flare-ups and remissions. There’s no cure, but treatments can control inflammation and reduce symptoms.

1. Ulcerative Colitis: Involves inflammation and ulcers in the lining of the colon and rectum.

2. Crohn’s Disease: Can affect any part of the GI tract, from the mouth to the anus, but most commonly impacts the end of the small intestine and the beginning of the colon.

Common Symptoms of IBD:

• Persistent and sometimes bloody diarrhea.

• Abdominal pain that is often in the lower right for Crohn’s, lower left for Ulcerative Colitis.

• Fatigue.

• Unexplained weight loss.

• Rectal bleeding.

• Fever.

• Joint pain, skin inflammation, or eye problems.

What is Irritable Bowel Syndrome?

IBS, on the other hand, is a functional disorder. It is more akin to a syndrome, which, by definition, is a group of symptoms, rather than a disease. The intestines look normal under a microscope and on scans. The problem with them is that they affect the way the gut works and how it communicates with the brain (the gut-brain axis).

IBS does not cause physical damage to the intestines, but it can significantly affect quality of life due to unpredictable and sometimes severe symptoms.

IBS is classified into three main subtypes based on the predominant symptoms:

• IBS-C: Constipation-predominant

• IBS-D: Diarrhea-predominant

• IBS-M: Mixed type (alternating constipation and diarrhea)

Common Symptoms of IBS:

• Abdominal pain or cramping that is often relieved by a bowel movement.

• Bloating and gas.

• Constipation, diarrhea, or both.

• Urgency to have a bowel movement.

• A sensation of incomplete evacuation.

Unlike IBD, IBS does not cause rectal bleeding, weight loss, or signs of inflammation. Lab tests and scans usually come back normal.

Causes and Risk Factors of IBD and IBS

IBS

IBS doesn’t have one single cause. Usually, it’s more like a mix of things that can throw your gut off balance. For some people, certain foods like dairy, gluten, or even specific sugars simply don’t agree with them. For others, it might be bacterial overgrowth in the intestines.

Your stress levels and emotional health can also play a significant role, as the gut and brain are constantly connected. If that communication gets a bit scrambled, your digestion can suffer. If you’ve got family members with IBS, your chances of experiencing it yourself can be a little higher.

IBD

With IBD, the story is a bit different. Genetics can play a strong part. If someone in your family has it, your risk of developing it increases. It’s also linked to immune system problems, where the body mistakenly attacks the gut.

Certain environmental factors can be triggers, too, like smoking or specific medications. An imbalance in your gut bacteria may also contribute to this condition. While stress doesn’t cause IBD, it can make flare-ups worse.

Diagnosis: How Doctors Tell Them Apart

While both IBS and IBD can cause similar digestive discomfort, the way doctors confirm each condition is quite different. IBS is diagnosed mostly based on symptoms. On the other hand, IBD requires medical tests to detect inflammation and possible damage to the gut.

IBS

• No single test confirms IBS.

• Diagnosis is based on symptoms and by ruling out other conditions.

• Rome IV criteria: Symptoms at least 1 day/week for the past 3 months, with the first signs starting at least 6 months ago.

IBD

• Requires medical tests to detect inflammation.

• Blood tests check for inflammation markers and anemia.

• Stool tests look for blood or signs of infection.

• Colonoscopy or endoscopy with biopsies to examine and sample the intestinal lining.

• MRI or CT scans help see the extent and location of inflammation.

Complications Of IBD and IBS

IBS Complications: Although IBS does not increase the risk of colon cancer, it can cause significant physical, emotional, and social impact, and the following complications

• Reduced quality of life

• Increased anxiety or depression

• Social and work limitations

• Chronic constipation or diarrhea leading to hemorrhoids.

IBD Complications: If not properly managed, chronic inflammation in the GIT can lead to the following serious long-term health problems

• Bowel perforation

• Intestinal strictures or blockages

• Fistulas, abnormal connections between tissues

• Malnutrition

• Increased risk of colon cancer over time

• Problems outside the GI tract (arthritis, skin disorders, liver problems)

Treatment Approaches

IBS Treatment:

For IBS, the focus should be on symptom control and trigger management.

• IBS-Constipation: Linaclotide, Lubiprostone, Plecanatide

• IBS-Diarrhea: Imodium, Eluxadoline, Alosetron, Rifaximin

• Diet: Low FODMAP diet, avoiding fatty foods, caffeine, and artificial sweeteners.

• Medications: Antispasmodics, anti-diarrheal drugs, fiber supplements, and certain antibiotics.

• Lifestyle: Stress management, regular exercise, and good sleep.

• Mind-Body Therapies: Cognitive Behavioral Therapy, Gut-Directed Hypnotherapy, and Meditation.

IBD Treatment:

For IBD, the goal is to reduce the inflammation and flare-ups.

• Medications:

o Anti-inflammatory drugs (mesalamine, corticosteroids)

o Immunosuppressants (Azathioprine, 6-Mercaptopurine (6-MP), Methotrexate)

o Biologic therapies (Infliximab, Adalimumab, Vedolizumab, Ustekinumab)

o Targeted small-molecule drugs (Tofacitinib)

• Surgery: For complications or severe cases (e.g., removing damaged bowel sections).

• Diet: Identifying and avoiding trigger foods, working with a dietitian during flare-ups.

Can You Have Both Conditions?

Up to half of people with IBD may also experience IBS symptoms. This overlap can be frustrating because you’re dealing with two different yet related problems simultaneously. When both conditions are present, the body is simultaneously managing inflammation and hypersensitive gut nerves. Some people with IBD, even when their inflammation is under control, may still have IBS-like symptoms. This is sometimes called IBS overlap in IBD or IBS-IBD overlap syndrome. Managing both can be tricky, as treatment has to address the inflammation from IBD and the gut sensitivity from IBS.

When to See the Doctor or Your Pharmacist

Red flags for immediate care:

• Blood in stool or persistent pain

• Unexplained weight loss

• Severe abdominal cramping or fevers over 100°F

Pharmacists can help you know when symptoms cross that line and provide OTC strategies while referring you for a doctor's visit.

The Bottom Line

While IBS and IBD can cause similar discomfort, they are not the same thing. You should be sensitive to each of the symptoms and ensure you get the best clarity on the condition.

• IBS affects how the gut works, but doesn’t damage it.

• IBD is an inflammatory disease that can cause lasting harm if untreated.

Both conditions are manageable with the right medical guidance, diet, and lifestyle adjustments. If you experience ongoing digestive symptoms, refrain from self-diagnosis. A gastroenterologist can help determine the cause and create a personalized treatment plan.

###