IBD vs IBS: Key differences, symptoms, diagnosis & treatment

If you’re unsure whether your symptoms point to IBD or IBS, you’re not alone. Many people in Ireland experience gut problems like pain, bloating, or diarrhoea and wonder which condition they might have.

On the surface they can seem similar, but the difference between IBS and IBD is significant. IBS (irritable bowel syndrome) is a functional disorder, meaning your bowel looks normal but doesn’t always work as it should. IBD (inflammatory bowel disease) is an inflammatory condition that can damage the bowel over time. 

Knowing how to tell if it’s IBS or IBD is key because each condition needs different treatment. In Ireland, your GP can carry out an appropriate assessment, which will include taking a detailed history and performing an examination. From there, they can decide what tests may be helpful. These might include blood tests, stool testing (such as faecal calprotectin), and imaging such as an ultrasound of the abdomen, CT scan, or MRI scan. 

They may also arrange a referral for investigations like a colonoscopy. In some cases, referral to a specialist, such as a gastroenterologist or colorectal surgeon, is required to help identify the cause of abdominal symptoms. If IBD is diagnosed, this will usually involve ongoing specialist care and support. 

Key Takeaways: IBD vs IBS

• IBD = Inflammation + bowel damage (e.g., Crohn’s, Ulcerative Colitis)

• IBS = Functional disorder (no inflammation or structural damage)

• IBD symptoms: blood/mucus in stool, fatigue, weight loss, fever

• IBS symptoms: abdominal cramping, bloating, bowel habit changes

• Diagnosis: blood tests, stool markers (e.g. calprotectin), colonoscopy

• Management: IBD requires specialist care; IBS focuses on dietary/stress triggers

Not sure what’s causing your symptoms? Talk to an online GP today

What is inflammatory bowel disease (IBD)? 

Inflammatory bowel disease vs irritable bowel syndrome is one of the most common confusions in gut health. IBD is a group of chronic conditions where the immune system attacks the digestive tract, leading to ongoing gut inflammation. Over time, this can cause lasting damage to the bowel wall [1]. 

The two main types are: 

• Crohn’s disease – can affect any part of the digestive tract, from mouth to anus, often in patches. 

• Ulcerative colitis – affects only the colon (large intestine) and rectum, with continuous areas of inflammation. 

IBD can be unpredictable, with flare-ups and periods of remission. During flare-ups, symptoms can become severe enough to require hospital care, especially if complications develop. 

Common IBD symptoms include: 

• Persistent diarrhoea, sometimes urgent 
• Blood or mucus in the stool 
• Abdominal pain or cramping 
• Unexplained weight loss 
• Fatigue that doesn’t improve with rest 
• Anaemia (low red blood cell count) 
• Fever during flare-ups [2] 

IBD can also cause issues outside the gut, such as joint inflammation, skin rashes, or eye irritation. Crohn’s & Colitis Ireland estimates that more than 40,000 people here live with IBD [1], and early treatment is vital to avoid long-term complications. 

What is irritable bowel syndrome (IBS)? 

IBS is a functional bowel disorder where the bowel looks normal on scans or scopes, but the way it moves and communicates with the brain is altered. This can lead to discomfort, changes in bowel habits, and other gut symptoms, without inflammation or structural damage. 

IBS symptoms can include: 

• Abdominal pain or cramping (often referred to as IBS pain location, which may shift) 
• Bloating and excess gas. Bloating vs inflammation is a useful distinction as bloating is common in IBS, inflammation points towards IBD. 
• Diarrhoea, constipation, or alternating between the two 
• Relief of symptoms after a bowel movement [3] 

IBS causes and triggers vary between people but can include stress, certain foods (such as high-FODMAP foods, caffeine, or fatty meals), hormonal changes, and previous gut infections. 

See our IBS flare-up guide for practical symptom management strategies.

While IBS doesn’t cause long-term bowel damage, it can have a significant impact on daily life and emotional wellbeing. Identifying your triggers can help you manage symptoms more effectively. 

Why IBS and IBD often get confused 

The IBS vs IBD confusion is understandable because both can cause abdominal discomfort, changes in bowel habits, and bloating. However, there are important differences: 

• Inflammation is present in IBD but absent in IBS 
• Bowel damage can occur in IBD but not in IBS 
• Blood in stool is common in IBD but rare in IBS 
• Weight loss, fever, and anaemia are linked to IBD, not IBS 

Because of these overlaps, diagnosis should never rely on symptoms alone. Only medical testing can confirm whether you have Crohn’s vs IBS, ulcerative colitis vs IBS, or IBS alone [4]. 

Comparing IBS vs IBD at a glance 

Symptoms that help distinguish IBS from IBD 

In IBS, bloating and cramping are often linked to meals, stress, or hormonal shifts. Pain tends to improve after a bowel movement, and bowel habits may swing between diarrhoea and constipation. Symptoms can change from day to day and don’t cause lasting harm to the bowel. 

In IBD, inflammation is behind the symptoms, making them more intense and persistent. Ongoing diarrhoea, especially at night, is common. Blood or mucus in the stool is a strong warning sign of inflammation. Weight loss, fatigue, and anaemia can also indicate IBD because inflammation interferes with nutrient absorption. 

Red-flag symptoms, such as blood in your stool, diarrhoea lasting more than a few weeks, unexplained weight loss, or persistent fatigue, should prompt urgent GP review in Ireland [5]. 

How are IBD and IBS diagnosed? 

Testing for IBS vs IBD starts with your GP, who will take a detailed history and look for patterns in your symptoms. 

IBS diagnosis is based on the Rome IV criteria, which assess how long you’ve had symptoms, how often they occur, and whether they improve after a bowel movement. 

Your GP will also check for alarm features such as blood in stool or weight loss, which suggest a condition other than IBS. Blood and stool tests are often used to rule out inflammation or infection. 

IBD diagnosis requires proof of inflammation, which may involve: 

• Blood tests for markers such as CRP or ESR 
• Faecal calprotectin stool test to measure bowel inflammation 
• Colonoscopy with biopsy to confirm the type and location of disease 
• Imaging such as MRI or CT scans, especially if Crohn’s disease is suspected outside the colon 

In Ireland, faecal calprotectin is increasingly used in GP practices to decide who needs urgent referral for colonoscopy, helping to shorten diagnosis times [11]. 

Treatment differences: IBS vs IBD 

IBS vs IBD treatment differences are significant because the underlying causes are not the same. 

IBS treatment focuses on managing symptoms and can include: 

• Diet changes such as a low-FODMAP plan under dietitian guidance 
• Stress reduction through mindfulness, CBT, or gentle exercise 
• Medications like antispasmodics or low-dose antidepressants for pain regulation 

IBD treatment should be supervised by a specialist such as a gastroenterologist. Treatment aims to control inflammation and prevent damage and may include: 

• Anti-inflammatory drugs such as 5-ASA medicines 
• Steroids to control flare-ups 
• Immunosuppressants or biologics to reduce immune activity 
• Surgery if medication is not effective or complications occur 

Diet and lifestyle tips for managing IBD and IBS 

Foods for IBS vs IBD differ because the underlying conditions are different. 

For IBS: 

• Follow a short-term low-FODMAP diet with dietitian support. Timing of meals is important too 
• Limit caffeine, alcohol, and fatty or processed foods 
• Keep a food and symptom diary to spot triggers 

For IBD: 

• Eat a balanced Mediterranean-style diet during remission 
• Avoid high-fibre, spicy, or hard-to-digest foods during flare-ups. Learn more about nutrition and hydration essentials.
  
• Stay well-hydrated, especially during diarrhoea 

For both: 

• Manage stress through breathing exercises, yoga, or walking. If you're trying to balance symptoms and weight, read our guide to sustainable weight management.
• Stay active at a comfortable level 
• Get regular sleep to support digestion and recovery [1] 

Living with IBS or IBD in Ireland: what to expect 

Both conditions can be managed with the right support. IBD often needs ongoing hospital-based care from a gastroenterologist, while IBS is usually managed in primary care [2]. 

Support is available from Crohn’s & Colitis Ireland, which offers information, patient stories, and local networks. Online GP services can provide fast access to advice and referrals. 

If you need help, book an online GP appointment for confidential, convenient advice.