Among all the diseases similar to IBD, most of the wrong diagnostics come when IBD gets confused with a case of irritable bowel syndrome (IBS). It’s easy to mix up these conditions: even their names are only a letter away from each other. They are very similar on the surface: both diseases cause chronic digestive problems and they share many of their symptoms like abdominal pain, bloating and diarrhoea. They even evolve in similar ways, with more or less frequent flare-ups followed by remission periods where patients experience few or no symptoms.

But, if we look closer at them, these diseases are very different. IBD is what it’s called a structural disease, which means there is a physical damage that causes the symptoms. Patients enduring IBD show inflammation, ulcers, and other damage within the digestive tract. Doctors can use tests like X-rays or endoscopies to see these signs and diagnose IBD. This physical manifestation of IBD can also make blood appear in the stools, a symptom that is absent in IBS. On the other hand, IBS is considered as a functional disease, that is, there are no visible damage that explains the symptoms. While it is known that IBD is an immune disorder, IBS causes remain unclear for doctors.

Ulcerative colitis or Crohn’s disease?

 As we noted in the beginning, IBD is an umbrella term that encompasses different conditions. The most common are ulcerative colitis and Crohn’s disease. We can find in both a chronic inflammation of the intestine and they share most of the symptoms, like frequent diarrhoea, blood in the stools or cramping. When a patient visits the physician’s practice, it’s precisely this symptom overlap what makes it difficult for doctors to tell Crohn’s disease apart from ulcerative colitis. But despite these similarities, colitis and Crohn’s show important differences between them.

One of the main disparities is where these diseases manifest themselves. The term colitis comes from colon, and that’s because ulcerative colitis happens in the large intestine. It affects usually the colon or rectum, although there are cases where the inflammation can affect the entire organ. Crohn’s disease, however, may happen anywhere along the digestive tract (i.e. from the mouth to the anus), although it often targets the small and large intestines.

Another difference is how the intestinal tissue is affected by inflammation. In ulcerative colitis, the inflammation is uniform and superficial. It usually affects only the mucosa of the intestine. On the other hand, Crohn’s affects the deeper layers of the gastrointestinal tract and it affects the mucosa and the inner muscle. In this condition, the tissue may develop patched areas, alternating affected and healthy zones. This gives the intestine a characteristic cobblestones aspect.


Finally, the complications that may arise are different between these conditions too. The presence of small areas of inflammation called granulomas and abnormal connections between organs called fistulas are more common in Crohn’s than in colitis. For these reasons, Crohn’s disease is generally considered more severe. In contrast, its global prevalence is much lower.

Spotting the differences is important because their treatments are different. As colitis happens only in the last part of the gut, a surgery to remove the colon can heal this disease completely. On the other hand, Crohn’s disease can happen all along the gastrointestinal tract, so surgery proves insufficient to cure it. Moreover, the available treatments for IBD don’t work the same in both conditions. For example, antibiotics are effective to treat Crohn’s, but they don’t show the same effect on ulcerative colitis.

Knowing what the characteristic features of IBD are is vital to walk towards finding a cure. There is certainly more to discover about this disease, but with each new piece of knowledge, research projects like New Deal will be closer to find a treatment to combat IBD for good.