Inflammatory Bowel Disease: Clinical findings in Crohn’s Disease
Authors: Yan Yu Amy Maghera Reviewers: Jennifer Au Danny Guo Jason Baserman Jessica Tjong Kerri Novak* * MD at time of publication
Behavioural Factors:
Smoking, over-sanitation
Genetic Susceptibility
Environmental Factors
Diet, bacteria/viruses, drugs, vitamin D
Systemic immune response primarily against the GI tract.
(Unclear mechanism, mediated by cytokine release and neutrophil inflammation)
Inflammation of the GI tract lining
– Inflammation is “transmural”, spanning the entire thickness of the intestinal wall from luminal mucosa to the serosa.
– The inflammation occurs anywhere in the GI tract from the oral mucosa to the anal mucosa (from ‘gums to bum’) in skip lesion pattern.
Atrophy, scarring of the intestinal villi
Inflammatory cytokines destroy the mucosa epithelial cells of the GI tract wall, causing cell apoptosis and ulceration
↑ permeability of the blood vessels supplying the GI tract wall
Chronic inflammation impairs healing responses
Dysregulated wound healingàexcess
extracellular matrix deposition
Fibrosis leads to scar tissue and thickening of all layers of the GI tract
Strictures
Inflammation is systemic, affecting:
Joints Arthropathy Erythema
Impaired absorption of nutrients
Weight loss
Prolonged GI bleeding
Anemia
Transporter proteins responsible for Na+ reabsorption gradually disappear from the epithelium
More sodium (and thus water) is
retained in the GI tract lumen
Microperforations can penetrate through the intestinal wall
Anal fistulae (“holes” connecting the anus to the skin, bladder, peritoneum, small bowel, etc.)
Continued inflammation and/or infection can lead to:
Leakage of fluid out of capillaries into the GI tract
Luminal edema and swelling
Narrowing of GI lumenàbowel obstruction
Skin
Mouth Eyes
Liver
nodosum, pyoderma gangreno- sum
>5 canker sores
Uveitis
Iritis, scleritis
Sclerosing cholangitis
↓ fat absorption
Fatty acids (negatively charged) bind Ca2+, freeing oxalate from Ca2+
↑ oxalate absorbed into blood & filtered by kidney
Calcium oxalate kidney stones
Diarrhea
Abdominal cramping and pain
(see Bowel Obstruction page for full mechanism
Anal abscesses Inflammatory masses
Legend:
Pathophysiology
Mechanism
Sign/Symptom/Lab Finding
Complications
Re-Published June 15, 2019 on www.thecalgaryguide.com