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Explaining Irritable Bowel Disease; Crohns, Colitis, Diverticulitis

There are so many terms relating to gut health - IBS, IBD, Crohn's, celiac, diverticulitis. It can be overwhelming, and if you're a suffer of poor gut health, knowing where to start can seem like a challenge.

In today's blog post I'm going to explain the difference between each and how they are diagnosed. Don't forget, to check out my other blog posts where I cover IBS and IBD in detail.

gastrointestinal health

Irritable Bowel Syndrome

What is it? IBS is where there is damage to the guy itself such as the lining, or an imbalance (sometimes called a dysbiosis) of the bacteria and gut flora present. Symptoms include constipation, diarrhoea, severe bloating, possible cramping, gas, foul-smelling stools and sometimes blood in stools. For some sufferers, symptoms are also coupled with sudden and urgent need to go to the bathroom. Essentially what many describe as a bad gut or leaky gut.

It can also be triggered by food poisoning, travel bug, antibiotic use, allergies and food intolerances.

How is it diagnosed? GPs can diagnose this and may use certain tests to verify such as a stool test, colonoscopy or endoscopy. Many people also self diagnose based on the common symptoms and the huge amount of research available online.

Irritable Bowel Disease

What is it? IBD is a more severe and chronic gut inflammation of the lining, intestinal bacteria and encapsulates other conditions such as Crohn's, Colitis and ulcers.

How is it diagnosed? IBD needs to be diagnosed by a GP or specialist.


What is it? Part of the IBD family, Crohn's disease is a lifelong condition where parts of the digestive system become inflamed. Symptoms can be similar to IBS - diarrhoea, stomach cramps, pain - but also fatigue and unexplained/extreme weight loss can also occur

How is it diagnosed? IBD needs to be diagnosed by a GP or specialist, where blood or stool tests may be used to test for inflammation.

Ulcerative Colitis

What is it? A long-term condition where the colon (sometimes called the bowel) and rectum become inflamed. Small ulcers can develop on the colon's lining, and can bleed and produce pus. Symptoms are similar to Crohn's and IBS, however due to more distressing symptoms of inflammation, fever-like symptoms can also occur such as rapid heartbeat, shortness of breath and a high temperature.

How is it diagnosed? Via a GP or gastrointestinal specialist who will do a physical examination and check for physical signs such as paleness due to anaemia or tummy tenderness. Further stool and blood tests similar to those used for Crohn's or IBS can also be used.

Stomach Ulcers

What is it? Have you heard of gastric or peptic ulcers? They are all similar terms for ulcers, or open sores, that develop on the lining of the stomach. They can also occur within the intestine - called duodenal ulcers.

Symptoms are less severe than IBS or IBD - commonly described as pain or burning across the stomach region. Heartburn, reflux, indigestion and nausea can also occur.

In some instances severe symptoms occur include vomiting blood. If this occurs, seek medical treatment immediately.

How is it diagnosed? Based on symptoms your GP can diagnose, but for confirmation a gastroscopy may be performed. Testing for a H. pylori infection may also be done via a urea breath test or blood test.

Diverticulitis & Diverticulosis

What is it? Diverticula are small bulges or pockets that develop in the lining of the intestine. If these don't present with any symptoms it is called diverticulosis. If these bulges become inflamed or infected it is called diverticulitis. Symptoms include stomach pain, constipation or diarrhoea.

It is believed to most commonly be caused by a lack of fibre.

How is it diagnosed? Often a simple scan can reveal if there are bulges present in the intestine. To test for diverticulitis, blood or stool test will be required to confirm infection. Your GP or specialist will also want to rule out IBS or IBD.

Looking for more information? Read more in my blogs here, or if you've already been diagnosed and looking for nutritional support you can book in a free 20 minute consultation with me today.


Kelly Mulhall

Registered Nutritional Therapist


Kelly is a Registered Nutritional Therapist who focuses on positive physical and mental wellbeing, achieved through diet, lifestyle, sleep and exercise. Having struggled for years with IBS and hormonal imbalance, and increasingly frustrated with the lack of support and helpful advice from her GP, Kelly began her own journey of healing the body from the inside out. After seeing huge improvements she quit her job to study nutrition and focus on harnessing the healing powers of food to help other people in similar situations.

I am not attempting to prevent, treat or cure any physical, mental or emotional issues. Do not disregard medical advice or delay seeking medical advice because of information you have read on this website. Do not start or stop taking any medications without speaking to your primary health care provider.

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