17-02-23 - Inflammatory bowel disease Flashcards
Learning outcomes
- Describe the clinical, gross and microscopic features of Ulcerative Colitis
- Describe the clinical, gross and microscopic features of Crohn’s Disease
- Relate signs and symptoms to the underlying pathophysiology
- Compare the features of UC/Crohn’s
How does IBD?
What are 7 common symptoms of IBD?
- Inflammatory bowel disease (IBD) is a term for two conditions (Crohn’s disease and ulcerative colitis) that are characterized by chronic inflammation of the gastrointestinal (GI) tract
- 7 Common symptoms of IBD:
1) Pain
* Can be present in different areas and at different times
* Often colicky pain
2) Diarrhoea
* Mucoid diarrhoea often present in UC
* Blood diarrhoea more common in UC
3) Lethargy
* Often due to fluid/nutrient loss
4) Weight loss
5) Fever
6) Constipation
7) Tenesmus
* Can sometimes feel the need to pass stool
What is IBS?
What are 3 features in those with IBS?
What is the gut-microbiota-brain axis?
What is it crucial for?
What can precede IBS development?
What kind of disorder is IBS?
How is IBS diagnosed?
- Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder
- 3 features in those with IBS:
1) Gastrointestinal motility response to external stressors
2) Abnormal visceral sensation (hypersensitive GIT)
3) Lower visceral pain threshold - The ‘gut–microbiota–brain axis’ refers to the network of connections involving multiple biological systems that allows bidirectional communication between gut bacteria and the brain
- It is crucial in maintaining homeostasis of the gastrointestinal, central nervous and microbial systems of animals
- Infectious diarrhoea may precede IBS development, as it can disrupt the gut–microbiota–brain axis
- IBS is a multi-system disorder, as it doesn’t just affect the GIT
- Diagnosis of IBS:
- 1 day/week in last 3 months of abdominal pain associated with ≥2 of –
1) Associated with defecation
2) Change in frequency of stool
3) Change in form of stool
Where do villi start to appear?
What is the surface of the rest of the GIT like?
How does the colon lubricate itself?
- Villi start to appear in the duodenum and end in the ileum
- The rest of the GIT has flat epithelium
- There are mucous glands in the colon to lubricate it
Describe the histology of the ileum.
Describe The histology of the villi of the small intestine.
1) Histology of the ileum:
* Mucosa is pale
* If it looks purple/blue, it can indicate a lot of inflammatory cells
* There are villi to increase the surface area for absorption
2) Histology of the villi of the small intestine:
* Epithelium cover the surface layer of villi
* The nuclei are at the bottom of tall columnar cells
* There are mucous producing goblet cells
* The centre of the villi has blood vessels that carry nutrients away and occasionally inflammatory cells
3) Histology of the colonic mucosa:
* Colonic mucosa has hand like structures which sit on top of muscularis mucosa
* The surface is quite flat with long crypts going down from the surface into the muscularis mucosa
* These are tall thin crypts with a flat surface on top
What are 4 types of causes of IBD?
- 4 types of causes of IBD:
1) Multifactorial
2) Genetic factors
3) Autoimmune / Immune dysfunction
4) Environmental factors
* External – smoking, pollution
* Internal - gut–microbiota–brain axis
What are 6 conditions associated with IBD?
- 6 conditions associated with IBD:
1) Indeterminate/unclassified colitis
2) Coeliac disease
3) Pseudomembranous Colitis
4) Diverticulitis
5) Appendicitis
6) Enteritis
What is the incidence and prevalence of UC?
At what age does UC typically present?
What groups does it commonly affect?
- Incidence of UC – 140 per million per year
- Prevalence of UC – 125-250 per 100,000 people
- UC typically presents in adolescence and early adulthood – median age 30 for diagnosis
- UC affects female more than males (due to being partially autoimmune) and non-smokers
Are symptoms of UC continuous?
What is UC characterized by?
Where does UC start in the colon?
How is inflammation of UC characterized?
What is pancolitis?
What are 3 signs of UC?
What is the appearance of UC like in the colon?
- UC is usually a relapsing/remitting course, meaning there are periods of being symptomatic and asymptomatic
- UC is characterised by inflammatory change in the colon
- UC starts in the rectum and progresses backwards, affecting a variable length of colon
- Inflammation in UC is Contiguous (continuous), circumferential, superficial inflammation
- Pancolitis is inflammation of the entire colon
- 3 signs of UC:
1) Anaemia – iron-deficiency
2) Raised inflammatory markers
3) Dehydration - UC in colon can appear with pseudopolyps (healing nodules) and ulcers (in picture)
How many inflammatory cells are in the lamina propria between crypts in the colon?
- In the lamina propria between crypts in the colon, it is relatively acellular, with few inflammatory cells
Describe the histology of UC
- Histology of UC:
- For UC all inflammation is superficial, so it will affect the epithelium and lamina propria (part of mucosa)
- It will sometimes affect just under the muscularis mucosa, but the submucosa and muscular layer don’t tend to be affected
- Flat surface
- Most cysts stop about half-way and don’t reach muscularis mucosa
- There are inflammatory cells present in crypts
- The lamina propria is densely packed full of inflammatory cells
- Neutrophils are sitting inside crypts and crypt epithelium
- These are crypt abscesses, which are an acute inflammatory response
- We often get ulceration in the gaps of epithelium and bleeding at the bottom of the ulcers
UC histology extra photo
What is the incidence and prevalence of CD?
At what age does CD present?
What groups does CD affect most commonly?
- Incidence of CD – 83 per million per year (half UC)
- Prevalence of CD – 145 per 100,000 people
- CD typically presents in adolescence and early adulthood – median age 30 for diagnosis
- CD more commonly affects females than males and smokers
Are symptoms for CD continuous?
How is the inflammation in CD characterised?
What are 3 commonly affected areas in CD?
What kind of ulceration and lesions do we see in CD?
Where do CD lesions typically begin?
- CD is usually a relapsing/remitting course, meaning there are periods of symptomatic and asymptomatic
- In CD, inflammation can occur anywhere in the GIT
- 3 commonly affected areas in CD:
1) Small intestine alone – 40%
2) Small intestine and colon – 30%
3) Colon alone – 30% - In CD, there is Discreet, focal ulceration
- There are skip lesions in CD, meaning there is gaps between them
- CD lesions typically begin in the terminal ileum, causing terminal ileitis
What are 3 conditions associated with CD?
- 3 conditions associated with CD:
1) Anaemia – Absorption/Blood Loss
* If the terminal ileum is affected, B12 will not be absorbed, which can results in iron deficiency anaemia, or anaemia or the chronic disease macrocytic anaemia (partially caused by B12 deficiency)
2) Raised inflammatory markers
3) Dehydration
Describe the appearance of CD on a colonoscopy.
Describe the appearance of CD from a barium enema fluoroscopy
- In a colonoscopy, CD presents with linear ulcers with normal tissue between, which sometimes looks nodular with pseudopolyps
- In barium enema fluoroscopy, CD gives a cobblestone appearance
How does CD affect fat positioning in the small intestine?
How can the lumen of the intestines be affected in CD?
What is this due to?
- In a normal small intestine, the external surface if the small intestine is bare, and fat will be attached to one edge
- In CD, fat tends to reach into the bare area and envelop the small intestine
- CD can cause strictures which can narrow the lumen of the intestines
- This is due to inflammatory and fibrotic reactions taking place in the intestinal wall, which can cause thickening and obstruction
Describe the histology of CD.
- The histology of CD.
- We get strictures because inflammation is full thickness and beneath the mucosa - this can trigger the recruitment of fibroblasts and myofibroblasts to the area for repair, leading to a more fibrotic healing process
- There is shortening of crypts and inflammation between crypts
- We look for granulomas, which are collections of histiocytes with giant cells, which are typical of CD
- There is ulceration with gaps in the epithelium
How can CD cause fistulas?
What 2 structures can a fistula form between?
What does this cause?
- In CD, ulceration and inflammation can breakdown structures all the way through the thickness of the bowel out to the skin
- A fistula can form bewteen the colon and the bladder
- This can lead to many STIs, which can affect the kidneys and ereters, and can also lead to farting penis
Which IBD disease is associated with extraintestinal manifestations?
What are 6 examples of IBD Extraintestinal Manifestations?
- UC is more often associated with Extraintestinal Manifestations
- 6 examples of IBD Extraintestinal Manifestations:
1) Inflammatory arthropathies
* Inflammatory arthritis (IA) is joint inflammation caused by an overactive immune system
2) Erythema nodosum (CD)
* Erythema nodosum (EN) affects the subcutaneous fat (septal panniculitis), causing tender erythematous nodules usually located on the shins
3) Pyoderma gangrenosum
* Breakdown of the skin
4) Primary sclerosing cholangitis (UC)
5) Iritis/Uveitis (CD)
* Eye problems
6) Aphthous stomatitis (CD)
* Mouth ulcers
Comparison of symptoms/signs of UC/CD:
* Abdominal pain
* Diarrhoea
* Weight loss
* Lethargy
* Fever
* Dehydration
* Tenesmus
* Involvement
* Extend
* Continuous?
* Wall involvement
* Ulceration
* Mesentery involvement
* Fissures/fistulae
* Crypts
* Crypt abscesses
* Villi
* Granulomas
* Cells
Describe the histology of Coeliac disease
- The histology of Coeliac disease:
- Villi in the small intestine can be flattened due to atrophy/shortening of the villi
- There is lengthening of crypts and lots of lymphocytes between and within the epithelium
What is pseudomembranous colitis caused by?
What groups is it common in?
How does it affect crypts of the large intestine?
- Pseudomembranous colitis is caused by C. difficile
- It is an infection that tends to occur in elderly patients who have had multiple antibiotics
- Crypts of the large intestine become inflamed and explode, causing colonic mucosa to spread over the surface of the colonic epithelium (hence the name pseudomembranous)
What are diverticula?
Who develops diverticula?
What is diverticulosis?
What causes diverticulitis?
How is diverticulitis treated?
- Diverticula are small bulges or pockets that can develop in the mucosa of the intestine, with most people developing them as they get older
- When there are no symptoms, it is called diverticulosis
- Diverticulitis is often caused when the outflow of diverticula is blocked, leading to faeces getting stuck and causing bacteria to grow
- This results in inflammation
- Diverticulitis is treated with antibiotics
What can cause ischaemic colitis?
How can it appear?
How can it be treated?
- Ischaemic colitis ca be caused by trauma to the abdomen
- The ischaemic portion of the colon can appear pale
- Sometimes, ischaemic colitis can be treated by taking out the ischaemic portion of the colon
What is appendicitis?
What does pain from appendicitis appear?
How is appendicitis treated?
- Appendicitis is inflammation of the appendix
- Appendicitis usually causes pain that starts in the umbilical region before moving towards the lower right groin region
- Those with appendicitis usually need surgery to remove the appendix as soon as possible.
