WEEKLY TOP 7 - Top 7 differences between UC & CD | InSimu Patient

WEEKLY TOP 7 - Top 7 differences between UC & CD

These days medical students are just flooded with a huge amount of information –different description of diseases, fresher and fresher publications – available online. It is really difficult to pick the clinically relevant data, especially when you do not have those years of practice behind your back. In our blog series You will find short and straightforward lists of clinical signs, symptoms which are the most typical and pathognomonic in certain diseases.

World IBD day takes place on 19 May each year. It aims to unite people in their fight against Crohn’s disease, Ulcerative colitis and other, less common inflammatory bowel diseases. We focus on these two conditions which are in some aspects quite similar to each other. We highlight the main differences, but we also mention the similarities.

1. Location

 

Ulcerative colitis

Crohn’s disease

Location

only affects colon

can affect the whole gastrointestinal tract

Rectum

almost always involved

usually spared

 

2. Clinical symptoms

These clinical signs can manifest in both diseases. However, some of them are more characteristic in one of IBDs - and that’s what we’d like to point out.

 

Ulcerative colitis

Crohn’s disease

loss of apetite, weight loss

present

present

nausea, vomiting

 

present

severe abdominal pain

rare

frequent

tenesmus

present

 

diarrhea

frequent

less frequent

blood in stool

frequent, with mucus

occasional

 

3. Extraintestinal manifestations

There are numerous extraintestinal symptoms of IBD. These manifestations vary in severity and can be more harming than the underlying IBD. While some extraintestinal manifestations parallel the disease activity (erythema nodosum, episcleritis), the course of others (pyoderma gangrenosum, uveitis) is independent of intestinal inflammation.

Common symptoms:

  • eyes: episcleritis, scleritis, uveitis, iritis
  • joints: polyarthritis, ankylosing spondylitis
  • bones: osteoporosis
  • skin: erythema nodosum, Sweet syndrome, pyoderma gangrenosum, etc.
  • kidney: kidney stones
  • anaemia

Main differences:

Ulcerative colitis

Crohn’s disease

primary sclerosing cholangitis (PSC)

gallstones

 

4. Endoscopy & histology

Even if the symptoms are non-specific, with colonoscopy and biopsy, the correct diagnosis can usually be made. However, in some cases, these tests are inconclusive, so ‘indeterminate colitis’ is the diagnosis.

 

Ulcerative colitis

Crohn’s disease

inflammation

continous

skip lesions

mucosal extension

mucosal

extended (mucosa and muscles)

bowel wall

thin with loss of vascular pattern

thickened, deep ulcers, swelling

granulomas

absent

present

white cells

polymorphs

lymphocytes

 

5. Complications

Unfortunately, IBD patients can develop severe complications which usually can only be solved by surgery. Colonic obstruction is the primary common complication. Let's see the differences:

Ulcerative colitis

Crohn’s disease

perforation

intestinal obstruction

fulminant colitis

abscesses

toxic megacolon

fistulas

increased risk of colorectal carcinoma

fissures

 

6. Diet

Ulcerative colitis

Crohn’s disease

unaffected by diet

remission can be achieved with enteral feed followed by exclusion/elimination diet

 

7. Smoking

Ulcerative colitis

Crohn’s disease

associated with non or ex-smokers

strongly associated with

appears to protect against disease

increases risk of surgery


Why? The relationship between smoking and IBD is complicated. To be honest, we don’t know why smoking has a protective effect against UC and why it is contraindicated in CD. There are many theories though:

  • Patients with UC have a thinner mucus layer in the large intestine. Nicotine may increase the production of this mucus. (UC)
  • Nicotine may suppress the immune system and prevent inflammation in the colon. (UC)
  • Nicotine releases nitric oxide which may reduce muscle activity in the colon and so reduce the need to go the toilet urgently. (UC)
  • Smoking can alter how a person’s genes are expressed. (UC, CD)
  • Smoking may change the bacterial flora that lives in the gut. (CD)

After learning the basics, test your knowledge in practice by solving the IBD Day Challenge with the InSimu Patient app! You can download it for iOS or Android.

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Sources:

https://www.uptodate.com/contents/clinical-manifestations-diagnosis-and-prognosis-of-crohn-disease-in-adults?search=ibd%20symptoms&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1
https://www.uptodate.com/contents/dermatologic-and-ocular-manifestations-of-inflammatory-bowel-disease?search=dermatologic%20and%20ocular%20manifestations%20of%20ibd&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1
http://www.crohns.org.uk/about_IBD/differences-between-crohns-disease-and-ulcerative-colitis
https://www.everydayhealth.com/crohns-disease/symptoms/key-difference-between-crohns-disease-ulcerative-colitis/
http://s3-eu-west-1.amazonaws.com/files.crohnsandcolitis.org.uk/Publications/smoking-and-IBD.pdf
http://www.ibdclinic.ca/what-is-ibd/complications/
http://www.ibdetermined.org/ibd-information/ibd-complications/intestinal-complications.aspx