Gastroenterology Flashcards
How can The causes of Upper GI bleeds be broken classified?
Oesophagus
Stomach
Duodenum
What are the Oesophageal causes of Upper GI Bleeds?
Oesophagitis
Varices
Malignancy
Gastro-oesophageal reflux disease (GORD)
Mallory-Weiss tear
What are the stomach causes of Upper GI Bleeds?
Peptic ulcer disease
Mallory-Weiss tear
Gastric varices
Gastritis
Malignancy
What are the duodenal causes of Upper GI Bleeds?
Peptic ulcer disease
Diverticulum
Aortoduodenal fistula
Duodenitis
What are some key causes for Upper GI bleeding?
Peptic ulcer disease (50%)
Oesophageal Varices
Mallory Weiss Tear
Cancers of stomach/duodenum
What is Peptic ulcer disease?
Break in the mucosal lining of the stomach, duodenum or lower Oesophagus more than 5mm diameter.
What can cause a peptic ulcer?
Imbalance between factors promoting mucosal damage and those promoting duodenal defence
What are some factors that cause mucosal damage and therefore increase risk of peptic ulcers?
Gastric acid - high volumes
H.Pylori
NSAIDs
Explain how H. pylori can lead to PUD?
Lives in gastric mucus
Secretes urease which splits urea in stomach into CO2 + ammonia
Ammonia + H+ 🡪 ammonium
Ammonium, proteases, phospholipases and vacuolating cytotoxin A damages gastric epithelium
Causes inflammatory response reducing mucosal defense 🡪 mucosal damage
Also causes increased acid secretion
Gastrin release (from G cells) 🡪 more acid secretion
Triggers release of histamine 🡪 more acid secretion
Increases parietal cells mass 🡪 more acid secretion
Decreases somatostatin (released from D cells) 🡪 more acid secretion
Explain how NSAIDs lead to PUD?
Mucus secretion stimulated by prostaglandins
COX-1 needed for prostaglandin synthesis
NSAIDs inhibit COX-1
No COX-1 = mucous isn’t secreted
Reduced mucosal defense 🡪 mucosal damage
Explain how Mucosal Ischaemia can lead to PUD?
Stomach cells not supplied with sufficient blood
Cells die off and don’t produce mucin
Gastric acid attacks those cells
Cells die 🡪 formation of ulcer
Treatment - H2 blocker
Explain how an increase in stomach acid can lead to PUD?
Overwhelms mucosal defence
Acid attacks mucosal cells
Cells die 🡪 formation of ulcer
Stress can increase acid production
Treatment – PPI and H2 blocker
Explain how Bile Reflux leads to PUD?
Duodeno-gastric reflux
Regurgitated bile strips away mucus layer
Reduced mucosal defense
What factors can increase acid production?
Stress
Alcohol
Caffeine
Smoking
Spicy Foods
What are some protective factors of the upper GI tract that are reduced that can lead to peptic ulcers?
Reduced Prostaglandins (NSAIDs) leading to poor muscosal production
Mucus damage (via H.pylori)
Bicarbonate loss leading to no neutralisation of stomach acid
What are the main areas where a Peptic Ulcer develops?
Gastric ulcer - stomach
Duodenal Ulcer
What is the most common area for a peptic ulcer?
Duodenal ulcers
What is the Classical Peptic Ulcer disease presentation?
The classical description of bleeding in PUD is of a posterior duodenal ulcer eroding through into the gastroduodenal artery.
Who is typically affected by peptic ulcers?
More common in men than women
Prevalence 11-20% for men
What are the risk factors for Peptic Ulcers?
Increasing age
H.Pylori infection
NSAIDS
Drugs - SSRIs, Corticosteroids
Smoking
Alcohol
What are the clinical signs of of peptic ulcer disease?
Evidence of bleeding
Hypotension
Tachycardia
Melaena
Epigastric Tenderness
Pallor - due to anaemia
What are some signs of Upper GI bleeding via peptic ulcers?
Burning Epigastric pain
Nausea & Vomiting
Haematemesis
Melaena
Reduced appetite
Weight loss
Fatigue - Anaemia
What is the pain like in an Upper GI bleed from a peptic ulcer?
How can this be used to distinguish the site of the ulcer?
Burning pain
Gastric ulcer - pain worsened by eating
Duodenal Ulcer - Pain relieved by eating and worse when hungry
What investigations would be done if the patient had no red flags/was not bleeding with a suspected peptic ulcer?
Urea breath test
Stool antigen test
Looking for H.pylori infection as a possible cause
If testing for H.pylori infection what must be done?
The patient must be off PPI for 2+ weeks to prevent false negative results
What are the investigations that you would do in a suspected peptic ulcer that is currently bleeding?
Upper GI endoscopy:
Diagnostic and therapeutic
FBC
U&E:
urea is raised
LFTs - Assess severity of Liver disease
Venous Blood Gas - raised lactate
Erect CXR - concerned about perforation
What is the Glasgow Blatchford Score (GBS)
Scoring system used in a suspected upper GI bleed. Those with a score of >0 require admission.
Drop in Haemoglobin
Rise in Urea
Systolic BP
HR
Melaena
Hx of Syncope
Hepatic disease Hx
HF
What is the Rockall Score?
Used for Px who have had an endoscopy. it is a % risk for rebleeding. considers:
Age
Features of Shock - Tachycardia/Hypotension
Co-morbidities
Causes of bleeding
Endoscopic Stigmata
What is the first line treatment for a peptic ulcer that is not bleeding?
Conservative Lifestyle Tx - treat RFs
H.pylori Neg:
PPI - omeprazole
H.pylori Pos:
Tripple Therapy - Omeprazole, Clarithromycin, Amoxicillin
What is the general management for an upper GI bleed?
ABATED:
ABCDE
Bloods
Access - 2 bore cannula
Transfuse
Endoscopy - urgent within 24 hrs
Drugs - Stop anticoagulants and NSAIDs
What is the first line treatment for a peptic ulcer that is bleeding?
First Line:
ABCDE
Blood transfusion - if blood loss
Upper GI endoscopy - within 24 hrs
High dose IV PPI - after Endoscopy
What is the Second line treatment for a Peptic ulcer which is bleeding?
Surgery or embolisation
What are some complications of peptic ulcer disease?
Perforation
Gastric outlet obstruction
peritonitis - caused by an ulcer/haemorrhage of an ulcer passing straight through into the stomach
Pancreatitis - can also occur as a result of peritonitis
What are the red flags for Cancer causing an Upper GI Bleed?
Unexplained weight loss
Anaemia
Evidence of GI bleeding e.g. melaena or haematemesis
Dysphagia
Upper abdominal mass
Persistent vomiting
What are Oesophageal Varices?
Dilated submucosal veins within the lower 1/3rd of the oesophagus that develop as a consequence of portal hypertension
What is the cause of oesophageal varices?
Portal Hypertension
What is the pathogenesis of oesophageal varices?
Portal HTN due to decompensated liver cirrhosis leads to increased back pressure into the left gastric vein.
This causes the veins draining the oesophagus to become engorged and dilate
They are then at increased risk of rupture causing an Upper GI bleed
Why are Oesophageal Varices prone to rupture?
As these vessels are thin and not meant to transport higher pressure blood, they can rupture
Rupture 🡪 haematemesis
Rupture 🡪 blood digested 🡪 melaena
What are the risk factors for oesophageal varices?
Liver Cirrhosis (50% of Px have varices)
Portal HTN
Decompensated liver Cirrhosis
What are the clinical signs of oesophageal varices?
Hypotension
Tachycardia
Pallor
Signs of chronic liver damage – jaundice, easy bruising (liver not produced coagulation factors) and ascites
Splenomegaly
Ascites
What are the symptoms of oesophageal varices?
Haematemesis
Melaena
Sx of blood loss:
Dizziness
dyspnoea
Chest pain
Syncope
What are the primary Investigations for oesophageal varices?
Upper GI endoscopy:
Diagnostic
FBC - Anaemia
LFTs - assess liver disease severity
U&Es - Urea is raised in upper GI bleed
What is the management for bleeding oesophageal varices?
Resus:
ABCDE
IV Fluids - if in shock
Blood transfusion
Terlipressin
Prophylactic Abx
Balloon Tamponade in emergency
What is Terlipressin and what does it do?
ADH analogue that can cause splanchnic vasoconstriction to reduce blood flow in the portal vein and reduce portal pressure
What Abx are given in oesophageal varices as prophylaxis?
Quinolones:
eg. ciprofloxacin
What is the definitive management of oesophageal varices?
1st line:
Variceal Band ligation
Sclerotherapy and transjugular intrahepatic portosystemic shunt (TIPS) are also able to be used
What prophylactic Tx should be given to prevent formation or rupture of oesophageal varices?
Beta blocker - propranolol to reduce portal pressure
Variceal band ligation
What are some complications of Oesophageal varices?
Rupture and GI bleeding
Rebleeding once fixed
Encephalopathy
Infection
What are the different classifications of bowel obstruction?
Site of blockage:
Simple
Intra luminal
In the wall
Outside the bowel
What are some causes of bowel obstruction?
Crohn’s
Adhesions
Malignancy
Diverticulitis
Volvulus
Hernias
Hirschsprung’s disease
What are some intraluminal causes of bowel obstruction?
Tumours:
- Carcinoma
- Lymphoma
Diaphragm disease - NSAIDs cause repeated ulceration then fibrosis
Gallstone ileus – rare form of small bowel obstruction caused by an impaction of a gallstone within the lumen
Meconium ileus – in neonates, content of bowel is sticky 🡪 blockage
What are some within the wall causes of Bowel obstruction?
Tumours
Crohn’s – inflammation, fibrosis and contraction
Diverticulitis – outpouchings in the sigmoid
What are some Outside the Bowel causes of Bowel obstruction?
Tumours – disseminated malignancy of peritoneum
Ovarian cancer can spread into peritoneum
Adhesions – fibrosis after surgery
Post-surgery
Fibrous connections between loops of small bowel 🡪 bowel becomes kinked
Corrected surgically
Volvulus – sigmoid colon has a “floppy” mesentery
Sigmoid colon can twist
Causes obstruction of the sigmoid
If there is ischaemia and infarction, sigmoid colon is resected
What are the main causes of a large bowel obstruction?
Malignancies - colorectal cancer (90% of all causes)
Stricture - complication of diverticulitis and IBD
Volvulus - Sigmoid / Caecal
Hirschsprung’s Disease
What is Hirschsprung’s Disease?
Congenital disorder where there is defective relaxation and peristalsis of the distal colon causing a bowel obstruction.
Neonates born with incomplete Innervation of the colon to rectum.
A ganglionic segments of the bowel cannot contract (peristalsis) leading to obstruction
What is a Volvulus and what are the 2 main types?
occurs when a loop of intestine twists around itself and the mesentery that supplies it, causing a bowel obstruction.
Sigmoid is most common (80%) - associated with elderly Px
Caecal is less common associated with Pregnancy and can occur at any age.
Define a small bowel obstruction (SBO)?
Inability of the gut to absorb the necessary nutrients sufficient to sustain life due to a mechanical blockage of the small intestine
What is the pathophysiology of a SBO (same for a LBO)?
Mechanical or functional obstruction of the small intestine preventing the normal passage of abdominal contents.
This leads to dilation of the proximal bowel and compression of mesenteric vessels.
Causes transudation of large volumes of electrolyte rich fluid into the bowel (third spacing).
Arterial supply is compressed and you get ischaemia
What is the most common indication for emergency laparoscopy?
Small bowel obstructions
What is the average age of a Px who has a small bowel obstruction?
70s
What are the main causes of a SBO?
Bowel adhesions (50%) - due to previous abdominal surgery
Incarcerated hernias (15%)
Crohn’s Disease
Volvulus - rarely SBO but commonly LBO
Paralytic ileus
Malignancy
What is a Pseudo-Obstruction of the bowel?
Where there is no blockage to the bowel however the intestine is unable to contract and push food, stool and air through the digestive tract
(Failure of Peristalsis)
How do surgeries lead to bowel adhesions?
Formation of fibrous scar tissue between organs and tissue can constrict and adhere to the bowel preventing expansion
What is a Paralytic Ileus?
Functional Obstruction due to failure of peristalsis:
Often caused post abdominal surgery
May also be due to electrolyte imbalances (hypokalaemia)
What are the clinical signs of a Large and small bowel obstruction?
Abdominal tenderness and distension
Tinkling bowel sounds
Rectal exam - empty or blood suggesting strangulation
Tachycardia
Hypotension
What are the symptoms of a small bowel obstruction?
Colicky pain - typically in umbilical region
Nausea and Vomiting - Early sign in SBO
Bloating/distension
Absolute constipation - Late sign in SBO
What are the Symptoms of a Large bowel obstruction?
Colicky generalised abdominal pain
Bloating
Absolute constipation - Early sign in LBO
Nausea and Vomiting - Late sign in LBO
What is a good way to distinguish whether a Px has a small or large bowel obstruction based off their Symptoms?
SBOs present with nausea and vomiting first before constipation
LBOs present with constipation first before nausea and vomiting
What is the cause of the pain felt in SBO?
When there is a mechanical obstruction to the SBO and peristalsis occurs this can lead to pain.
Which tests are ordered in the diagnosis of Large/small bowel obstruction?
CT Scan - diagnostic for an obstruction
FBC - anaemia/infection
U&Es - Likely have renal dysfunction secondary to hypovolaemia
Venous blood gas/Lactate - may be increased
CRP/ESR - inflammatory
Potentially Gastrograffin contrast scan
What is the gold standard diagnostic test for a Large/small bowel obstruction?
CT Scan:
Diagnostic
Location and cause may also be indicated
What is the treatment for all patients with a Large/small bowel obstruction?
Manage pain - analgesia and anti emetics
Assess fluid balance - NG tube/ Urinary catheter
IV Fluids
Nutrition if > 5 days without intake.
What is the treatment for patients with a small bowel obstruction due to adhesions?
Signs of Ischaemia or Shock:
Resus and Operate
No-ischaemia:
Gastrografin challenge and determine whether there is a need to operate
What is the treatment for all patients with a small bowel obstruction due to a hernia?
Inguinal/Femoral/Umbilical - operate and repair
Incisional Hernia - Treat as adhesive SBO
What are the complications of a Small Bowel Obstruction?
Intestinal necrosis
Sepsis
Multi-organ failure particularly renal
Intestinal perforation
What are the 2 types of oesophageal cancer?
Adenocarcinoma
Squamous cell carcinoma
What type of oesophageal cancer is most common?
Squamous cell carcinoma (90%) in upper 2 thirds
What most commonly predisposes Oesophageal adenocarcinoma?
Barret’s metaplasia where glandular columnar epithelium replaces the squamous epithelium in the lower oesophagus
What is the location of an adenocarcinoma of the Oesophagus?
Lower third of the oesophagus near gastro-oesophageal junction
What is the location of a Squamous cell carcinoma of the oesophagus?
Usually upper or middle third of the oesophagus
What are the risk factors for adenocarcinoma of the Oesophagus?
Barrett’s Oesophagus
GORD
Obesity
Smoking
Coeliac Disease
Scleroderma
What are the risk factors for SSC of the oesophagus?
Smoking
Alcohol
Achalasia
Plummer Vinson syndrome
Hot beverages
Nitrosamines
Who is more commonly affected by oesophageal cancer?
Males
80 years old
Western world
SSC is more common in Japan
What are the clinical signs of oesophageal cancer?
Lymphadenopathy
Vocal Cord Paralysis
Pallor - anaemia
Melaena - due to oesophageal bleeding
What are the symptoms of oesophageal cancer?
ALARMS:
Anaemia
Loss of Weight
Anorexia
Recent sudden Sx worsen
Melaena/Haematemesis
Swallowing - Progressive Dysphagia
Hoarse Voice - due to pressure on recurrent laryngeal nerve
What may be a differential diagnosis when a Px presents with symptoms of dysphagia?
Achalasia
This however is non progressive and so Px dont say at first it was difficult to swallow then fluids then food etc.
What is the primary investigation for oesophageal cancer?
Upper GI Endoscopy (OGD) and Biopsy
Staging Ix:
CT Chest abdo pelvis (CAP)
Endoscopic ultrasound (EUS)
HER2 Testing
What is the first line staging investigation for oesophageal cancer?
CT chest, abdomen and pelvis (CAP)
What is the management of Oesophageal cancer for both Adenocarcinoma and SCC?
If operable:
Adenocarcinoma - Oesophagectomy
SCC - Radical chemoradiotherapy
Advanced/Metastatic:
Chemotherapy
Palliation - Stenting for Dysphagia
Trastuzumab for HER2 Positive
When does Oesophageal cancer tend to present and what is the prognosis?
Tends to present late
Has a prognosis of 15% 5yr survival
What are the main types of cancer is a gastric cancer?
Adenocarcinoma (90-95%)
SCC (5%)
What are the main types of Adenocarcinoma Gastric cancer?
Type 1 (Intestinal) - Usually exophytic or ulcerating
Type 2 (Diffuse) - Flat, causing linitus plastica
What are the features of Intestinal Gastric cancer?
Better Prognosis
Exophytic
Ulcerating lesions
Well formed and differentiated glandular structures
What are the features of Diffuse gastric cancer?
Has a much worse prognosis
Poorly cohesive
Infiltrates the gastric wall
Can affect any part of the stomach
What are the modifiable risk factors for Gastric cancer?
H.pylori infection (significant)
smoking
alcohol
diet
Obesity
What are the non-modifiable risk factors for gastric cancer?
Genetics - CDH-1 gene (mutated Cadherin)
Male
Increased age
Pernicious anaemia
Blood type A
Gastric Adenomatous polyps
Where is gastric cancer most common?
Japan
What are the clinical signs of gastric cancer?
Fe Deficiency anaemia - Koilonychia
Palpable mass
Melaena
Leser-Trelat sign - sudden onset keratosis
What are the symptoms of gastric cancer?
Severe epigastric Abdominal pain
Dyspepsia
Anorexia and weight loss
Dysphagia
Nausea and vomiting
Signs of Metastasis - Liver dysfunction etc
What are the main lymph nodes that Gastric cancer may spread to?
Virchow’s Node - Supraclavicular
Sister Mary Joseph Node - Umbilical
What is the primary investigation of gastric cancer?
Upper GI Endoscopy and Biopsy
1st line staging - CT-CAP
What is the management of Gastric cancer?
Surgery only indicated if no evidence of metastatic disease
Surgery - remove tumour/stomach
Advanced disease:
Chemotherapy - 5-Fluorouracil/Cisplatin
Palliative gastrectomy
What are some complications of Gastric cancer?
Bleeding
Gastric outlet obstruction
Perforation
Metastasis
What is Bowel Cancer?
Usually an adenomatous cancer that typically affects the colon (colorectal) more than it affects the small bowel
What is the prevalence of bowel (colorectal) cancer?
4th most prevalent cancer in the UK.
Behind breast, prostate and lung
3rd most Prevalent world wide
How do bowel cancers arise?
sporadic cancers arising from:
Adenomatous Polyp to progress to adenocarcinoma
Defects in DNA repair genes
What are the risk factors for Bowel cancer?
50+
Increasing age
Smoking
Obesity
IBD
FHx - FAP, HNPCC
What is Familial adenomatous Polyposis (FAP)?
Autosomal dominant
Malfunctioning tumour suppressor genes of APC (adenomatous polyposis coli)
Leads to many Polyps developing which can progress to cancer
What is the pathogenesis of FAP?
Apc bound to GSK
Beta catenin binds apc complex in high levels of apc
In mutations, apc protein misfolded so can’t bind to beta catenin
Beta catenin able to move into nucleus 🡪 endothelial proliferation 🡪 adenoma
What is Hereditary Nonpolyposis Colorectal Cancer (HNPCC)?
Lynch syndrome
Autosomal dominant
Mutations in DNA mismatch repair genes (MMR)
Increases the risk of multiple cancers particularly colorectal
What are the 2 broad areas of colorectal cancers?
Left sided (LS) Colorectal cancer
Right Sided (RS) colorectal cancer.
These may have different signs and Sx
What are the symptoms of Left sided bowel cancer?
General Cancer Sx
Change in bowel habit with blood and mucus in stools
Diarrhoea
Alternation constipation and diarrhoea
Thin/altered stool
What are the Symptoms of Right sided colorectal cancer?
Usually asymptomatic until they present with iron deficiency anaemia due to bleeding
May present with a mass
Weight loss
Abdominal pain
What are the clinical signs of Bowel cancer?
LS CC - rectal mass, PR bleeding
RS CC - Iron Deficiency anaemia
What is the Diagnostic investigation used for Bowel cancer diagnosis?
FIT Test - screening test for micro blood particles in faeces
Gold standard - Colonoscopy and Biopsy
Digital Rectal exam
38% of colorectal cancers can be detected by DRE
1st Line staging - CT-CAP
What is the FIT test?
Faecal immunochemical Test for bowel cancer screening:
Looks for Hb in stool.
Performed in anyone over 50 with unexplained Weight loss and no other symptoms.
Performed in over 60s with a change in bowel habit
What is the staging classification for bowel cancer?
TNM Dukes staging:
Tumour: TX - T4
Nodes: NX-N2
Metastasis: M0-M1
What is the Dukes staging of Bowel Cancer?
Duke stage:
A – 95% 5 year survival, limited to muscularis mucosae (mucosa)
B - 75% 5 year survival, traverses bowel lining and into submucosa (not lymph)
C - 35% 5 year survival, involvement of regional lymph nodes
D - 10% 5 year survival - mets
What is the Treatment for Bowel cancer?
Surgical resection - curative if no mets
+ chemotherapy
What are some differential Diagnoses of Colorectal Cancer?
Anorectal pathology
Haemorrhoids
Anal fissue
Anal prolapse
Colonic pathology
Diverticular disease
IBD
Ischaemic colitis
Small intestine and stomach pathology
Massive upper GI bleed – haematochezia
Meckel’s diverticulum
What is Dyspepsia?
Functional Dyspepsia is a form of a Functional Gut disorder like IBS where there are Sx of Indigestion without any other clear cause.
Dyspepsia can also be a symptom of certain conditions such as PUD
What are the Sx of Dyspepsia?
Early satiation
Epigastric pain and Reflux (like GORD)
Heartburn
Bloating
Hoarse Cough
Extreme Fullness.
What is the Epidemiology of Dyspepsia?
Common – affecting up to 25% of population a year
What is the cause of Dyspepsia?
Functional Dyspepsia - Unknown Cause.
Other causes may be PUD.
What are the diagnostic investigations for Dyspepsia?
Endoscopy is used to find an underlying cause.
If there is no obvious cause then it may be functional dyspepsia
What is the Treatment for Dyspepsia?
If underlying cause then Tx.
If functional - Give reassurance and dietary review.
What is a Mallory-Weiss Tear (MWT)?
Longitudinal lacerations limited to the mucosa and submucosa
Found at the border of the gastro-oesophageal junction (GOJ)
What is the pathophysiology of a MWT?
Dilations and tears caused by a sudden rise in intra abdominal and transmural pressure across the GOJ secondary to vomiting and retching in the presence of pre existing gastric mucosal damage.
What are the risk factors for MWT?
Any condition that predisposes retching/vomiting:
Gastroenteritis, Bulimia etc.
Alcoholism
Chronic cough
Hiatus hernia
GORD
Who is typically affected by a MWT?
Male with acute Hx of retching after a night out.
40-60yrs
What are the symptoms of a MWT?
Preceding retching and vomiting
Haematemesis
Melaena - rare
Epigastric pain
What are the primary investigations for a MWT?
Upper GI endoscopy
FBC - anaemia
U&Es - raised urea
What is the management of a MWT?
Usually self limiting - manage contributing factors
If persistent bleeding:
Upper GI endoscopy - clipping/thermal coagulation
High dose IV PPI (pantoprazole) - give after endoscopy
What is the difference between a MWT and an oesophageal varices?
A MWT is caused by increased intraabdominal/transmural pressures that cause tears in preexisting mucosal damage.
An oesophageal varices is a consequence of portal HTN due to decompensated liver failure which causes dilation of the oesophageal blood vessels that then become prone to rupture.
Both can cause an upper GI bleed
What are some differential Diagnoses for a Mallory Weiss Tear?
Gastroenteritis
Peptic ulcer
Cancer
Oesophageal varices
If you have a patient with acute haematemesis what should you consider?
Hx of Liver disease + portal HTN = Oesophageal Varices
No Hx of liver disease but acute Hx of Retching = MWT
Describe h.pylori.
A gram negative bacilli with a flagellum that is present in 50% of the populations gastric mucosa
How does helicobacter pylori infection cause gastric damage?
Lives in gastric mucus
Secretes urease which splits urea in stomach into CO2 + ammonia
Ammonia + H+ 🡪 ammonium
Ammonium, proteases, phospholipases and vacuolating cytotoxin A damages gastric epithelium
Causes inflammatory response reducing mucosal defense 🡪 mucosal damage
Also causes increased acid secretion
Gastrin release (from G cells) 🡪 more acid secretion
Triggers release of histamine 🡪 more acid secretion
Increases parietal cells mass 🡪 more acid secretion
Decreases somatostatin (released from D cells) 🡪 more acid secretion
What conditions can arise as a result of H.pylori infection?
Peptic Ulcer Disease (PUD)
Gastritis
Gastric carcinomas
What is the diagnostic test to investigate H.pylori infection?
1st line: Urea breath test
Stool antigen test
What is the treatment of H.pylori infection?
Triple-therapy: For 7 days
Proton Pump Inhibitor - Omeprazole
Clarithromycin
Amoxicillin
What is Inflammatory bowel disease?
Umbrella term for 2 main diseases causing inflammation of the GIT Tract.
Ulcerative Colitis and Crohn’s Disease.
What is Crohn’s Disease?
Form of IBD
Granulomatous inflammation of any part of the gut
Characterised by Skip lesions arising anywhere between the mouth and anus.
Transmural inflammation with granuloma formation
What can cause Crohn’s Disease?
NOD-2 mutation
Bacterial immune mediated response - TNFalpha, IL-1, IL-6
What are the features of Crohn’s Disease?
Crohn’s (Crows NESTS):
N - No Blood or mucus in stool
E - Entire GI Tract - from mouth to anus can be affected
S - Skip Lesions on Endoscopy
T - Terminal Ileum is most affected and Transmural inflammation
S - Smoking is a risk factor - dont set the nest on fire
CHRISTMAS:
C - Cobblestones
H - High temperature
R - Reduced lumen
I - Intestinal fistulae
S - Skip lesions
T - Transmural
M - Malabsorption
A - Abdominal pain
S - Submucosal fibrosis
Where is the most commonly affected region of the GI tract in Crohn’s Disease?
The Terminal ileum and colon.
What is the inflammation like in Crohn’s Disease?
Transmural - full thickness
Occurs in skip lesions (points of inflammation and no inflammation) across GIT
Can lead to fistulas, Strictures and adhesions
What are the Micro and Macro features of Crohn’s Disease?
Macroscopically
Skip lesions
Cobblestone appearance due to ulcers and fissures in mucosa
Thickened and narrow
Microscopically
Transmural – affects all layers of bowels
Non-caseating granulomas (aggregations of epithelioid histiocytes)
Goblet cells
Who is typically affected by Crohn’s Disease?
Highest incidence and prevalence in Northern Europe, UK and North America
F>M
Presents mostly at 20-40
What are the risk factors for Crohn’s Disease?
FHx - NOD2 mutation
Caucasian
Female
HLA-B27
Smoking
Chronic Stress
What are the signs of Crohn’s Disease?
Abdominal tenderness
Fever
Malabsorption
Blood, fistulas, fissures on PR exam
Aphthous - mouth ulcers
Extra-intestinal Manifestations: (less common in Crohns’)
Erythema nodosum
Anal fissures
Episcleritis
What are the symptoms of Crohn’s Disease?
Diarrhoea
RLQ abdominal pain (ileum)
Fatigue, fever, Nausea, vomiting
Tenderness
What is Ulcerative Colitis?
Form of IBD
Inflammation of the rectum which extends proximally but never beyond the ileocecal valve.
Mucosal and Submucosal inflammation with crypt abscesses and neutrophil infiltration.
What can Cause Ulcerative Colitis?
Unknown aetiology
NSAIDs - associated with IBD onset and flares
Potentially autoimmune as it is associated with HLA-B27 gene and pANCA
Where is the most commonly affected region in Ulcerative colitis?
Only affects the rectum (proctitis) and continuous colon.
Never past the ileocecal valve to the small bowel
What is the inflammation like in Ulcerative Colitis?
continuous inflammation of the Large bowel.
Mucosal and Submucosal layers are affected (not transmural)
Can lead to crypt abscesses and neutrophil infiltration.