GI Flashcards
UC: Pathophysiology / what does it look like under a mc? / histology?
- Crypt abscess.
- Increase in plasma cells in the lamina propria.
Continuous inflammation affecting ONLY the mucosa.!!!!
Microscopic:
• Mucosal inflammation - inflammation DOES NOT GO DEEPER e.g. transmural
UC: management?
Anti-inflammatories
For mild/moderate UC:
Mesalazine.
UC: define?
Affects which part of bowel? (3 TYPES)
which affects ONLY the COLON
Relapsing and remitting inflammatory disorder of the COLONIC MUCOSA
- may affect just the rectum - proctitis (50%) - most common!!!
- rectum and left colon - left-sided colitis (30%) !!!
- entire colon (entire large bowel) UP TO the ILEOCAECAL VALVE - pancolitis/extensive colitis (20%)
UC: complications?
- Colon: blood loss and colorectal cancer.!!!!
- JOINTS - Arthritis., ANKYLOSING SPONDYLITIS!!
- EYES - Iritis and episcleritis.
- Fatty liver and PRIMARY SCLEROSING CHOLANGITIS!!!
- SKIN — Erythema nodosum.
UC: epidemiology?
PROTECTIVE FACTORS?
Higher incidence than Crohn’s per year
Affects males and females equally
Is 3 times more common in NON/EX SMOKERS - symptoms may relapse on stopping of smoking!!!
Is a PROTECTIVE FACTOR against UC
Appendicectomy = also PROTECTIVE FACTOR
Cause is UNKNOWN
UC: symptoms?
- Runs a course of remissions and exacerbations
- Restricted pain usually in LOWER LEFT QUADRANT
- Episodic or chronic diarrhoea with blood and mucus
- Cramps
- Bowel frequency linked to severity
- In acute UC there may be fever, tachycardia and tender distended abdomen
- In acute attack patients have bloody diarrhoea (passing 10-20 liquid stools per day), diarrhoea also occurs at night, with urgency and incontinence that is severely disabling
- Extraintestinal signs; clubbing, aphthous oral ulcers, erythema nodusum (red round lumps below skin surface)and amyloidosis
UC: investigations?
Gold standard?
Blood tests:
• White cell count and platelets raised in moderate/severe attacks
• Iron deficiency anaemia
• ESR and CRP raised
• Liver biochemistry may be abnormal
• Hypoalbuminaemia is severe disease
• pANCA (Anti-neutrophilic cytoplasmic antibody) may be positive (in Crohn’s this is negative)
Stool samples; to exclude C.diff and Campylobacter etc. - Faecal calprotectin - indicates IBD but not specific
Colonoscopy with mucosal biopsy:
• GOLD STANDARD for diagnosis
• Allows for assessment of disease activity and extent
• Can see inflammatory infiltrate, goblet cell depletion, crypt abscesses and mucosal ulcers
Abdominal X-ray:
Useful when UC too severe for colonoscopy
CD: define
can affect ANY PART of the GI tract (mouth-anus)
A chronic inflammatory GI disease characterised by transmural (goes deep into mucosa) granulomatous inflammation affecting ANY part of the gut from mouth to anus (especially in TERMINAL ILEUM and PROXIMAL COLON)
Unlike in UC, there is unaffected bowel BETWEEN areas of active disease - these are SKIP LESIONS
CD: Pathophysiology / histology?
Patchy, granulomatous, transmural inflammation (can affect just the mucosa or go through the bowel wall - Inflammation EXTENDS through ALL LAYERS (transmural) of the bowel).
Macroscopic:
• NOT CONTINUOUS i.e. there are SKIP LESIONS/patchy areas where there is a gap between affected and unaffected mucosa
Granulomas present in 50-60% - these are non-caseating epithelioid cell aggregates with Langhans’s giant cells
Increase in chronic inflammatory cells and there is lymphoid
hyperplasia
• Less crypt abscesses’ than UC
CD: aetiology? And risk factors?
Cause is UNKNOWN but
May be caused by
BUT could be caused by a non-functioning mutation in NOD2!!!!!
- Genetic association is stronger in CD than in UC:
• Mutations on NOD2 (CARD 15) gene on chromosome 16 increases risk - Smoking
- NSAIDs may exacerbate disease
- Family history
- Chronic stress and depression triggers flares
- Good hygiene - those who live in poor hygiene families have a lower risk of developing CD
- Appendicectomy may increase the risk of CD development
CD: symptoms?
- Diarrhoea with urgency (need to go 5-6 times in 45 mins), bleeding and pain due to deification
- Abdominal pain - can present as an emergency with acute right iliac fossa pain mimicking appendicitis SOMETIMES RIF PAIN!!!
- Weight loss
- Malaise
- Lethargy
- Anorexia
- Abdominal tenderness/mass
- Perianal abscess
- Anal strictures
- Extraintestinal signs; aphthous oral ulcerations, clubbing, skin, joint & eye problems
CD: investigations?
-
Examination:
• Tenderness of RIGHT ILIAC FOSSA
• Anal examination -
Bloods:
• Anaemia is common due to malabsorption and thus deficiency of iron and folate- However, despite terminal ileal involvement, B12 anaemia is unusual
• Raised ESR and CRP
• Raised white cell count and platelets
• Hypoalbuminaemia present in severe disease as part of an acute phase response to inflammation associated with a raised CRP
• Liver biochemistry may be abnormal
• NEGATIVE pANCA
- However, despite terminal ileal involvement, B12 anaemia is unusual
- Stool sample to exclude C.difficile and Campylobacter - Faecal calprotectin - indicates IBD but not specific
-
Colonoscopy:
• Biopsy to confirm will see spot lesions and granulomatous transmural inflammation - Upper GI endoscopy:
• Exclude oesophageal and gastroduodenal disease
CD: management?
Anti-inflammatories
- Smoking cessation
- Anaemia due to iron, B12 or folate should be treated with replacement
Mild attacks:
• Controlled-release corticosteroids e.g. BUDESONIDE -
]
Moderate to severe attacks:
• Glucocorticoids e.g. ORAL PREDNISOLONE - reduce dose every 2-4 weeks if symptoms resolve
Severe attacks:
IV HYDROCORTISONE
Maintain remission:
• AZATHIOPRINE - side effects; bone marrow suppression, acute
pancreatitis and allergic reactions
• METHOTREXATE if intolerant of azathioprine
Surgery:
• 80% require surgery at some point
• Avoided and only minimal resection
IBS: define
Denotes a mixed group of abdominal symptoms for which no organic cause ca be found
A FUNCTIONAL BOWEL DISORDER
IBS: epidemiology?
- Age of onset is under 40
- More common in FEMALES than males
- Common, in western world around 1 in 5 report symptoms consistent with IBS -
- Symptoms are exacerbated by stress, food, gastroenteritis or menstruation
IBS: aetiology?/TRIGGERS
- Depression, anxiety
- Psychological stress and trauma •
- GI infection
- Sexual, physical or verbal abuse •
- Eating disorders
IBS: 3 types?
IBS-C - with constipation
• IBS-D - with diarrhoea
• IBS-M - with constipation and diarrhoea
IBS: Pathophysiology?
Multi factorial pathophysiology
The following factors can all contribute to IBS:
- Psychological morbidity / mood / stress e.g. trauma in early life.
- Abnormal gut motility.
- Genetics.
- Altered gut signalling (visceral hypersensitivity).
Also altered gut microbiota
And post GI infection
IBS: symptoms?
- ABDOMINAL PAIN!
- Bloating.
- Change in bowel habit.
(Top 3)!!!!
ABC!!!! - Pain is relieved on defecation. !!!!!
- Mucus.
- Fatigue.
Painful period
• Urinary frequency, urgency, nocturia and incomplete emptying of bladder
• Back pain
Symptoms are chronic (more than 6 months) and exacerbated by stress, menstruation or gastroenteritis (post-infection IBS)
IBS: DDx?
- Coeliac Disease
- Lactose intolerance.
- Bile acid malabsorption.
- IBD.
- Colorectal cancer.
IBS: investigations?
- Bloods - FBC (anaemia), U+E, LFT.
- CRP. —> inflammation
- Coeliac serology. —
Colonoscopy to rule out IBD or colorectal cancer
Faecal calprotectin - raised in IBD
IBS: management?
For mild IBS?
Moderate IBS>
Severe IBS?
MILD IBS
Education, reassurance, dietary modification e.g. FODMAP.
MODERATE IBS Pharmacotherapy and • Psychological treatment - Antispasmodics for pain. - Laxatives for constipation. - Anti-motility agents for diarrhoea. - CBT and hypnotherapy.
SEVERE IBS:
MDT approach, referral to specialist pain treatment centres.
- Tri-cyclic anti-depressants.
In someone with coeliac disease, what are they most likely to be deficient in - iron, folate, or B12?
Iron.
Coeliac disease mainly affects the duodenum and iron is absorbed in the duodenum. Folate is absorbed in the jejunum and B12 in the terminal ileum.
Coeliac Disease: pathophysiology????!!!
Name the break down product of gluten digestion that can trigger coeliac disease.
Duodenum is mainly affected by coeliac disease
T-cell mediated autoimmune disease of the small bowel in which PROLAMIN (alcohol-soluble proteins in wheat, barley, rye and oats) intolerance causes villous atrophy and malabsorption
Gliadin (product of gluten digestion) = immunogenic.
It can have direct toxic effects by up-regulating the innate immune system or HLADQ2 can present it to T helper cells in the lamina propria -> inflammation -> villi atrophy -> malabsorption.
Gliadin.
Coeliac Disease: symptoms?
Suspect in all if they have??
SUSPECT in ALL with DIARRHOEA, WEIGHT LOSS or ANAEMIA (especially if iron or B12 deficient)
- Diarrhoea.
- Weight loss.
- Irritable bowel.
- Iron deficiency anaemia.
- Mouth ulcers. !!!!!!!!!!!!
- Abnormal liver function.
Steatorrhoea - stinky/fatty stool!!!!!!!!!!!!!!!
Abdominal pain
N and V
- Osteomalacia - softening of bones due to impaired bone metabolism due to lack of phosphate, calcium and vitamin D leading to OSTEOPOROSIS (40-60% risk in untreated patients leading to fracture risk)
- Dermatitis hepetiformis - red raised patches, often with blisters that burst on scratching, commonly seen on elbows, knees and buttocks!!!!!!!!!!!!!!!!!!!
1/3 are asymptomatic (silent disease) and only detected on routine blood tests (raised MCV)
Coeliac Dx: investigations?
Gold standard?
What 3 histological features are needed in order to make a diagnosis of coeliac disease?
- Serology - look for auto-antibodies - TTG and EMA.
- Both are IgA antibodies
- These correlate with the severity of mucosal damage and can thus be used fro dietary monitoring - Gastroscopy - duodenal biopsies. - -gold standard!!
Duodenal biopsy is the gold standard for diagnosis:
• See villous atrophy, crypt hyperplasia and increased intraepithelial
white cell count - seen histologically
• All reverse on gluten free diet
FBC:
• Low Hb
• Low B12
• Low ferritin
- Raised intraepithelial lymphocytes.
- Crypt hyperplasia.
- Villous atrophy.
Coeliac Dx: risk factors?
What disorders might be associated with coeliac disease?
- IgA deficiency
- Breast feeding
- Age of introduction to gluten into diet
- Rotavirus infection in infancy increases risk
And below !!
Other autoimmune disorders: since having one will increase risk of others:
1. T1 diabetes.
- Thyroxoicosis.
- Hypothyroidism.
- Addison’s disease.
Osteoporosis is also ckmnly seen in those w coeliac
Coeliac Dx: epidemiology?
- Around 1% of population affected
- Occurs at any age but peaks in infancy and 50-60yrs
- Affects males and females equally
Coeliac Dx: management?>
Lifelong gluten free diet i.e. no prolamins - use serum antibody testing for monitoring:
• Eliminate wheat, barley and rye - results in days/weeks
• Poor compliance is main reason for recurrent issues
• Oats usually tolerated unless contaminated with flour during production • Meat, dairy product, fruits and vegetables are all gluten-free
Correction of vitamin and mineral deficiencies e.g. B12, folate, iron, calcium and vitamin D
DEXA scan to monitor osteoporotic risk
GORD: symptoms
- Heart burn.
- Acid reflux.
- Dysphagia.
Belching
- Food/Acid brash (food, acid or bile regurgitation)
- Water brash (increased salivation)
- Odynophagia (painful swallowing)
Extra-oesophageal:
• Nocturnal asthma
• Chronic cough
• Laryngitis (hoarseness and throat clearing) • Sinusitis
GORD: define and pathophysiology????!!
reflux of stomach contents (acid with/without bile) causes troublesome symptoms (defined as 2 or more heartburn episodes a week) and/or complications
Reflux of gastric contents is normal but when there is prolonged contact of gastric contents with the mucosa this results in clinical symptoms
GORD: management?
- PPI. 2ND LINE = H2 ANTAGONISTS EG RANITIDINE And other meds —- antacids, alginates,
- Lifestyle modification.
Encourage weight loss
• Smoking cessation
• Small, regular meals
• Avoid; hot drinks, alcohol, citrus fruits and eating less than 3 hours before be - Anti-reflux surgery.
GORD: aetiology?
- Lower oesophageal sphincter hypotension •
- Hiatus hernia:
- Sliding hiatus hernia (80%):
• Where the gastro-oesophageal junction and part of the stomach ‘slides’ up into the chest via the hiatus so that it lies above the diaphragm
• Acid reflux often happens as the lower oesophageal sphincter become less competent in many cases
- Rolling or para-oesophageal hiatus (20%):
• Where the gastro-oesophageal junction remains in the abdomen but part of the fundus of the stomach prolapses through the hiatus alongside the oesophagus
• NOTE: as the gastro-oesophageal junction remains intact, reflux is UNCOMMON - Loss of oesophageal peristaltic function •
- Abdominal obesity
- Gastric acid hypersecretion
- Slow gastric emptying
- Overeating •
- Smoking
- Alcohol
- Pregnancy - results in increased abdominal pressure
- Fat, chocolate, coffee or alcohol ingestion
- Drugs e.g. antimuscarinic, calcium channel blockers and nitrates • Systemic sclerosis
Barrett’s Oesophagus: define
when squamous cells undergo meta plastic changes and → become COLUMNAR CELLS
There is always a hiatus hernia present
Barrett’s Oesophagus: Complications?
And describe how Barrett’s leads to this?
Risk of progressing to oesophageal cancer - its premalignant for
adenocarcinoma!!!!! of the oesophagus
- GORD damages normal oesophageal squamous cells.
2. Glandular columnar epithelial cells replace squamous cells (metaplasia).
- Continuing reflux leads to dysplastic oesophageal glandular epithelium.
- Continuing reflux leads to neoplastic oesophageal glandular epithelium - adenocarcinoma.
Barrett’s Oesophagus: aetiology?
- GORD
2. Obesity
Mallory Weiss Tear: define?
- DefinitionThis is a linear mucosal tear occurring at the oesophagogastric junction and produced by a sudden increase in intra-abdominal pressureIt often follows a bout of coughing or retching and is classically seen after
alcoholic ‘dry heaves’
Mallory Weiss tear: management?
- most bleeds are minor and heal in 24 hours
- Haemorrhage may be large but tend to stop spontaneously
- If surgery is required then it involves the oversewing of the tear but this is rarely needed
Mallory Weiss tear: investigation and symptoms?
Endoscopy to confirm
- Vomiting
- Haematemesis after vomiting -
- Retching
- Postural hypotension
- Dizziness
What can helicobacter pylori infection cause?
H.pylori produces urease -> ammonia -> damage to gastric mucosa -> neutrophil recruitment and inflammation. This can cause gastritis; peptic ulcer disease and gastric cancer.
peptic ulcer: aetiology?
- Prolonged NSAID use -> decreased mucin production.
- H.pylori infection.
- Hyper-acidity.(Increased gastric acid secretion )
Smoking (minor)
Delayed gastric emptying
Peptic ulcer: symptoms?
Often acute onset of symptoms:
1. Pain. Recurrent burning epigastric pain:
- Bleeding.
- Perforation.
- • Pain of duodenal ulcers classically occurs at night (as well as during the
day) and is worse when the patient is hungry
• Pain in both gastric and duodenal ulcers can be relieved by antacids- Gastric ulcer = pain inc when eating and goes away 2-3 hrs later
- Duodenal ulcer = pain decreases when eating and causes pains several hours after eating!!
Peptic ulcer: Investigations?
- H.pylori test e.g. urease breath test and faecal antigen test.
- Gastroscopy.
- Barium meal.
Peptic ulcer: Management?
Why are all gastric ulcers re-scoped 6-8 weeks after treatment?
- Stop NSAIDS.
- PPI’s e.g. omeprazole.
- H.pylori eradication.
All peptic ulcers are re-scoped to ensure they’ve healed. If they haven’t healed it could be a sign of malignancy.
Achalasia: define and symptoms?
is a rare disorder of the food pipe (oesophagus), which can make it difficult to swallow food and drink
- Dysphagia for fluids and solids
- Regurgitation of food particularly at night and aspiration pneumonia is a complication
- Substernal cramps
- Weight loss - but is usually minimal
- Spontaneous chest pain occurs and is said to be due to oesophageal ‘spasm’; it may be misdiagnosed as cardiac pain
Achalasia: investigations? CONFIRMS DX??
-
CXR:
• Dilated oesophagus
• May be fluid level behind/above the heart -
Barium swallow:
• Shows lack of peristalsis
• Lower end shows a ‘birds beak’ due to failure of sphincter to relax -
OESEOPHAGEAL Manometry:!!!!!!!
• Confirms diagnosis
• Shows aperistalsis of the oesophagus and failure of relaxation of the lower oesophageal sphincter - CT & Oesophagoscopy used to rule out carcinoma at the lower end of the oesophagus which can produce a similar x-ray appearance
Acute mesenteric Ischaemia: define
and symptoms?
1st line investigation:
- -symptomaticischemia* without irreversible tissue damage* caused by insufficient blood supply to the gastrointestinal tract.
- divided into embolic, thrombotic, or venous
- –affects small intestine
Classical clinical TRIAD:
- Acute severe abdominal pain - tends to be constant, central or around the right iliac fossa
- No abdominal signs on exam
- Rapid hypovolaemia resulting in shock - pale skin, weak rapid pulse, reduce urine output, confusion
- NOTE: the degree of illness is often far out of proportion with clinical signs
!!!!!If you see ATRIAL FIBRILLATION (AF) with abdominal pain then think MESENTERIC ISCHAEMIA
investigatiosn:
CT!! (MRI) angiography:!!!!!! 1st LINE!!!
• Provides non-invasive alternative to simple arteriography
Laparotomy (surgical procedure → cut into abdominal wall → access to abdominal cavity):
• To make diagnosis
• May see necrotic bowel if not treated quickly
Bloods:
• Raised Hb due to plasma loss
• Raised white cell count
• Persistent METABOLIC ACIDOSIS
Ischaemic Colitis: define and aka?
pathophysiology and most commonly affected site?
aka chronic colonic ischaemia
inflammation and injury of the large intestine result from inadequate blood supply.
Usually follows low flow in the inferior mesenteric artery (IMA) territory and ranges from mild ischaemia to gangrenous colitis
Sudden drop in blood flow -> insufficient perfusion -> poor oxygen/nutrient delivery to bowel -> compromised cellular metabolism -> ischaemia, inflammation, infarction, nerosis
Affects the large bowel
- Occlusion of branched of the superior mesenteric artery (SMA) or inferior mesenteric artery (IMA), often in the older age group
- The anatomy of the vascular supply to the colon results in a watershed area at the splenic flexure - which is thus the MOST COMMON SITE AFFECTED
ischaemia colitis: symptoms?
- Sudden onset Left Iliac Fossa pain
-
Signs of hypovolaemic shock
- Sudden onset lower LOWER LEFT SIDE abdominal pain
- Passage of bright red blood with/without diarrhoea
- May be signs of shock (pale skin, weak rapid pulse, reduce urine output, confusion) and evidence of underlying cardiovascular disease
Decreased bowel sounds, guarding + rebound tenderness
Ischaemic colitis: investigations and gold standard~?
- Urgent CT scan to exclude perforation
- Flexible sigmoidoscopy:
• Biopsy shows epithelial cell apoptosis
!!!!!!!!- Colonoscopy and biopsy - GOLD STANDARD:
• Only done AFTER patient has fully recovered to exclude stricture
formation at the site of disease and confirm mucosal healing
- Barium enema:
• Thumb printing of submucosal swelling at splenic flexure
management = antibiotics and fluid resusucitaion
Appendicitis: define and pathophysiology?
painful swelling of theappendix
Theappendixis a small, thin pouch about 5 to 10cm (2 to 4 inches) long.
Occurs when the lumen of the appendix becomes obstructed by lymphoid hyperplasia, filarial worms or a FAECOLITH (most common) resulting in the
invasion of gut organisms into the appendix wall
- This leads to oedema, ischaemia, necrosis and perforation as well as INFLAMMATION
- If the appendix ruptures then infected and faecal matter will enter the peritoneum resulting in life threatening peritonitis