IBD, IBS and Small intestine Flashcards
Conditions in IBD
Crohn’s disease
Ulcerative colitis
What are the causes of IBD
Idiopathic, but genetics + environment + immunity have been claimed to have an effect on development of IBD
What genes are claimed to have an impact on IBD
NOD2 , HLA-DR2, HLA-DQw5
Risk factors for Crohn’s
Young age Male Family history of IBD NSAID Smoking
How may the immune system have an effect on development of Crohn
Predominantly TH1 response (TH1 > TH2)
excess TNF-alpha (proinflammatory cytokine)
Difference between Crohn’s disease and ulcerative colitis
- Crohn’s affect anywhere in GI tract whereas UC only affects rectum and colon
- Crohn’s causes transmural inflammation whereas UC only causes submucosal inflammation
- Crohn’s causes skip lesions whereas UC is continuous inflammation
- Crohn’s is associated with mouth ulcers whereas UC is not
- Smoking increases risk of Crohn’s whereas smoking protects against UC
- Crohn’s forms non-caseating granuloma whereas UC does not have any granuloma
Most common site of Crohn’s disease
small intestine
Which age group is at most risk for Crohn’s
Younger people, 10-40 years old
And elderly 60-80 years old
What are the pathophysiological changes seen in Crohn’s
- cobblestone pattern
- patchy, discontinuous inflammation
- non-caseating granuloma
- rosethorn ulcers
What causes cobblestone pattern in crohn’s
Ulcers connecting together
What causes rose thorn ulcer appearance in IBD
Transmural inflammation of Crohn’s disease
What does transmural inflammation mean
Inflammation across all layers of mucosa
What are the histological findings for Crohn’s
Non-caseating granuloma Inflammatory cells bursting into crypts Lymphoid hyperplasia Increase in inflammatory cells in lamina propria loss of crypts Increase in goblet cells
What do macrophages look like under microscope
Pale pink cytoplasm
Symptoms of Crohn’s disease
Diarrhea +/- blood Vomiting Weight loss Abdominal pain Pale due to anaemia tender abdomen
Which site of inflammation causes pain in peri umbilical region
small intestine
Which site of inflammation causes lower abdominal pain
Colon
Diagnosis for Crohn’s
Blood tests Stool culture Faecal calprotectin colonoscopy / upper gi endoscopy small bowel MRI
What would blood tests show if the patient has IBD
Increase in CRP
Decrease in albumin
Decrease in Hb
Why do we need to measure faecal calprotectin
To differentiate between IBD and IBS
What will the faecal calprotectin level be in IBD
Elevated
2 main objectives in managing Crohn’s
To induce remission
To maintain remission
Because this is a lifelong disease, there will be exacerbations and remissions, goal is to induce and maintain remission
First line drug to induce remission in Crohn’s
Glucocorticoids - prednisolone or IV hydrocortisone
Why isn’t steroids used in young children
Because it causes stunted growth
Second line drug to induce remission in Crohn’s
Azathioprine / methotrexate / mercaptopurine
First line drug used to maintain remission in Crohn’s
Azathioprine / mercaptopurine
When is methotrexate used in maintaining remission
In Crohn’s disease when azathioprine / mercaptopurine are not tolerated or ineffective
Surgery is curative in Crohn’s disease or UC
UC
When is surgery used in Crohn’s
for fistula repair / perianal repair / stricturoplasty
What should surgeons be cautious about when dealign with Crohn’s
Limiting the amount resected to avoid e.g. short bowel syndrome causing malabsorption
What are the complications of Crohns
Stricture of bowel Perforation Fistula Malabsorption / gall stones Anal diseases Increases risk for colonic cancer amyloidosis Continous diarrhea
Why may perforation and fistula occur in Crohn’s
Due to transmural inflammation
How may Crohn’s disease increase risk of gall stone formation
1) Reduces ability to reabsorb bile acids = Decreases enterohepatic recycling
2) Depletion of bile acids
3) decrease in cholesterol absorption
4) cholesterol collect in gall bladder and because gall bladder concentrates bile, excess cholesterol may become crystalized and form gall stones
What is a fistula
When the fissure penetrates through the adjacent organ and forms an abnormal connection
What is vesicocolic fistula
Fistula between colon and bladder
Examples of anal diseases caused by Crohns’
fissures
abscesses
What is amyloidosis
Abnormal build up of amyloid in organs, disrupting function
How does smoking affect UC
Protects against UC
Pathophysiological changes in UC
Crypt abscesses Branching and irregular crypts Inflammatory infiltration into lamina propria Continuous inflammation Loss of goblet cells
What may low grade activity of UC eventually lead to
Persistent inflammation -> fibrosis -> loss of crypts -> no longer functional
Which type of T cell is associated in development of UC
Th2
Symptoms of UC
Diarrhea + blood
Need to go to toilet for a lot of times
tenesmus
abdominal pain at left iliac fossa
When do UC symptoms usually occur
At night
What is tenesmus
feeling to pass stool even though you already did
What is Truelove and WItts used for
assess severity for UC
What is considered as mild in Truelove and Witts
pass stools for < 4 times
small amount of blood
What is considered as intermediate in Truelove and Witts
pass stools for 4-6 times
mild - severe amount of blood
What is considered as severe in Truelove and Witts
pass stools for more than 6 times
bloody
pyrexic / tachycardic / increase in ESR
What is ESR
erythrocyte sedimentation rate ; measures the distance red blood cells travel in one hour in a sample of blood as they settle to the bottom of a test tube
What does elevated ESR mean
Inflammation
First line management of mild UC
topical or oral aminosalicylate
Second and third line management of mild UC
if 5ASA ineffective = + oral prednisolone
If 5ASA + steroid ineffective = + oral tacrolimus
First line management of severe UC
IV corticosteroids
Second line management of severe UC
+ IV ciclosporin
or surgery
Complications of UC
Toxic megacolon
Increases risk for colorectal carcinoma
Hypokalaemia
Extra GI manifestations
What is toxic megacolon
When the colon swells up and fills up with fluid due to inflammation. It can eventually burst and release all contents into peritoneal cavity -> peritonitis, sepsis, death
What is the urgent treatment for toxic megacolon
Immediate colectomy
Which IBD condition increases risk for colorectal cancer more
UC
What does the extent of increase in risk of colorectal cancer depend on
The more colon is affected , the greater the risk
Having UC for over 10 years
Extra GI manifestations of IBD
Eyes - uveitis
Liver - primary sclerosing cholangitis (UC)
joints - arthritis, ank spondylitis, clubbing
skin - painful purple nodules on skin (erythema nodosum), aphthous ulcer
anaemia , thromboembolism
Which extra GI manifestation is the most common due to UC
Arthritis
What is IBS
functional bowel disease characterised by abdominal pain and altered bowel habits
What does functional bowel disease mean
There are no structural / biochemical dysfunction. Most likely due to dysregulation in communication between the gut and brain
Causes of IBS
Abnormal motility
Visceral hypersensitivity
Altered gut flora
Altered mucosal and immune function