What is the Difference Between Crohn’s Disease and Ulcerative Colitis?

Approximately 80,000 Australians suffer from Inflammatory Bowel Disease (IBD), with 60% of IBD patients aged under 40. Both Crohn’s disease (CD) and ulcerative colitis (UC) are the most common types of IBD. They affect both genders equally and share similar signs and symptoms, but they are not the same disease.

The main difference between Crohn’s and UC is the location of the inflammation within your digestive system. Other differences include the type of inflammation, the pervasiveness of the disease, and surgery treatments. To learn more about the differences between these two types of IBD, read on.

Location of the Inflammation

Crohn’s disease is a severe inflammatory disease with unknown causes. It affects the tissues in your gastroesophageal tract (from the mouth to the rectum), causing them to become inflamed. The location and severity of inflammation differ from one case to another, and the symptoms can range from mild to severe. These may include sudden weight loss, diarrhoea, fever, cramping, nausea, and bloody stools. In most cases, patients suffer from bouts of diarrhoea and abdominal pain. This may be followed by remission of other symptoms. Unfortunately, there is no cure for this disease, but medications may be used to keep the symptoms at bay.

Ulcerative colitis is an intense and chronic inflammatory disease with unknown causes as well. However, the location of inflammation is restricted only to the large intestine or colon. Symptoms may include some of those of Crohn’s although the abdominal pain predominantly takes place in the left side along with large amounts of blood or pus in the stool and difficulty defecating despite feeling an urgent need to do so. Surgical removal of your large intestine is one possible treatment for UC, but the post-surgery complications might outweigh the benefits, especially for older patients.

To put it simply, Crohn’s disease can take place anywhere along your gastroesophageal tract, while UC is restricted only to your large intestine.

Type of Inflammation

Ulcerative colitis causes a continuous inflammation exclusively in your large intestine region. Conversely, Crohn’s disease causes discontinuous inflammation with intervening sections of normal and healthy tissues along your gastroesophageal tract.

Differences in the Signs and Symptoms

The symptoms associated with Crohn’s and UC depend on several factors, such as the severity of the disease and the location of the inflamed tissues within the colon or GI tract. Moreover, ongoing treatments and bacterial infection may also cause some changes in your diagnosis from UC to CD.

Based on a 2007 study, UC patients with either weight loss or non-bloody diarrhoea as early symptoms have an increased risk of subsequent change in diagnosis to Crohn’s in comparison to those who have none of these symptoms. Additionally, fever, weight loss and tachycardia may occur in patients with a severe and long history of UC, albeit these symptoms are more frequently found in CD patients.

Rectal and perianal diseases like skin tags and haemorrhoids may develop in patients with IBD. Those with UC typically develop rectal problems due to chronic and prolonged diarrhoea as well as other unrelated disorders, but they are more common in patients with CD. In CD patients, these problems are often the result of severe CD relapse or transmural complication.

In a 2008 study, researchers characterised the anal skin tags of 169 IBD patients, 62% of whom are diagnosed with CD, in an attempt to distinguish the morphological features of CD and UC. They have concluded that 75% of anal skin tags are classified as Type 1 (elephant ears) and they are associated with CD. On the other hand, both UC and CD patients may develop Type 2 anal skin tags as these skin growths showed no preference for any type of IBD. Skin tags normally occur because of healed anal ulcers, fissures, and haemorrhoids.

Therefore, a specialist may be able to differentiate UC from Crohn’s depending on where your signs and symptoms typically occur and how severe your condition is. The bottom line is that even after your initial assessment, further diagnosis may still be required to really identify which type of IBD you’re suffering from.

Read more: Ulcerative Colitis Symptoms And Treatment

The Pervasiveness of the Disease

Not only can Crohn’s occur anywhere in your digestive tract, but it also takes place in the sublayers of your intestines, including the rectum. UC, on the other hand, can only develop within the innermost lining of your large intestine.

So, which is worse?

While both CD and UC are chronic inflammatory diseases, the latter may be considered as the “worse” type of IBD, as patients with severe and prolonged UC may need surgical treatments. Worse still, older patients (aged 50 and above) who need surgery have increased risk for mortality because of the UC-associated post-surgery complications.

Surgical Treatments

Restorative procto-colectomy with ileal-pouch-anal-anastomosis (IPAA) is one of the most effective treatments for patients with UC. Even patients who suffer from long-term remission of symptoms may benefit from IPAA and experience an improved quality of life.

However, unfortunately, this isn’t the case for most patients with Crohn’s disease, as they tend to develop complications after undergoing IPAA treatment. These patients may develop pouchitis, perianal abscess, and 50% may need pouch revision.

The Takeaway

Ulcerative colitis and Crohn’s disease are two of the most common types of IBD. They have similar signs and symptoms, but the two are not alike in other ways. Their major difference lies in the areas of the digestive system they affect. UC is confined to the large intestine or colon, while CD causes discontinuous inflammation along the gastroesophageal tract, with sections of healthy tissues. They may also differ in terms of severity, risk factors (e.g., bacterial infection that could alter your initial diagnosis from UC to CD), and to an extent, the corresponding treatment options.

If you are experiencing signs and symptoms of IBD, we highly recommend seeing a specialist in order to rule out other disorders so you can arrive at a proper diagnosis and start your treatment immediately. Surgery may be required to treat UC, while medications may be used to help promote remission, prevent UC and CD flare-ups, and improve your quality of life.

Need Our Help?

Book an appointment with an accredited dietitian or nutritionist by phone on (07) 3071-7405 between 8am and 6pm Monday to Friday or send us an enquiry. Alternatively, learn more about our Gut and Bowel Health services.

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