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GI Diseases - Coggle Diagram
GI Diseases
Oesophagus
GORD
Epidemiology
Most common cause of oesophagitis
Pathogenesis
Abnormal retrograde movement of stomach contents into oesophagus normally prevented by
Lower oesophageal sphincter
Anatomic structure
Oesophageal peristaltic clearance
Swallowed saliva
-Gravity
Risk factors
Decreased sphincter tone
Sliding hitatal hernia
Decreased Oesophageal clearance / increased saliva production
Lying down
Hiatal hernia
Sliding
Para-oesophageal
Diagnosis
Clinical
Heartburn
Endoscopic
Red / congested mucosa
Manometric
Decreased sphincter pressure
Ph <4
Pathological
Microscopical evidence
Complications
Ulceration
Haemorrhage
Perforation
Fibrotic stricture
Barett's
Barrett's Oesophagus
Definition
Characterised by replacement of normal stratified squamous mucosa by metaplastic columnar epithelium containing goblet cells - intestinal metaplasia
Causes
Longstanding GORD
Reflux
Complications
Risk of dysplasia and adenocarcinoma progression
Infective oesophagus
Fungal
Pathogen
Candida
Presentation
Inflammation
Erosions
Ulcers
Risk factors
Immunocompromised
DEbilitated pts
Broad spectrum antibiotics
Viral
Pathogen
Herpes simplex virus
Pathogenesis
Infects squamous cells causing cell death
Presentation
Vesicles
Erosions
Ulceration
Risk factors
Immunosuppression
Debilitated pts
Achalasia
Types
Primary
Rare idiopathic
Loss of inhibitory innervation of LES - failure to relax
Secondary
Chagas disease - Trypanosoma cruzi
Destruction of myenteric plexus
Presentation
Progressive dysphagia
Bolus obstruction
Aspiration
Mega-oesophagus
Risk of SCC
Aperistalsis
Incomplete relaxation of LES with swallow
Increased resting tone of LES
Bird beak appearrance on barium swallow
Pill oesophagitis
Definition
Chemical injury to oesophagus by medication
Causes
KCI
NSAIDs
Tetracyline
Clindamycin
Oral biphosphonates
Iron
Pathogenesis
Pill held in oesophagus
Increased contact time
Chemical nature of medication
Dependant on size, solubility, coatig
Less common with newer pill design
Eosinophilic oesophagitis
Epidemiology
Cronic
Children and ypung adults
Symptoms
Prolonged before diagnosis is established
Dysphagia
Food bolus obstruction
Chest
pain
Heart burn
Reflux type symptoms
Associtions
Allergy + Atopy
Atopic dermatitis
Allergic rhinitis
Asthma
Eczema
Coeliac disease
Triggers
Cows milk
Eggs
Wheat
Pollen
Pathogenesis
Exposure to allergen
Th2 pattern of inflammation - IgE
Treatment
Avoid allergens
PPIs
Immunosuppression
Topical steroid
Anti IL-5
Dilation
Varices
Definition
Esophageal varices are extremely dilated sub-mucosal veins in the lower third of the esophagus
Causes
Chronic liver disease
Liver cirrhosis
Presentation
PRotrusion of overlying mycosa into oesophageal lumen
Haematemesis
Melaena
+/- Hypotensive shock
Complications
Haemorrhage
Mallory Weizz Tear
Definition
Longitudinal tears in oesophageal wall due to prolonged forceful vomiting /retching
Complications
Rupture - Boerhaave syndrome
Pathology by aetiology
Congenital
Atresia
Stenosis
Fistulas
Webs
Aquired
Toxic
GORD
Pill oesophagitis
Neoplastic
Barrett's
Adenocarcinoma
Squamous cel carcinoma
Infection
Fungal
Viral
Chagas disease
Idiopathic
Achalasia
Immunological
Eosinophilic oesophagitis
Vascular
Oesophgeal varices
Trauma
Mallory Weiss Tear
Stomach
Acute Gastritis and Acute Stress Ulcers
Pathogenesis
Acute mucosal inflammatory process
Depletion of mucosal protection system
Acid / enzyme injury to mucosa
Complications
Acute erosions
Ulceration
Bleeding
Perforation
Risk Factors
NSAIDs - Aspirin
Excess
Alcohol
Heavy smoking
Chemotherapy
Trauma
burns
, surgery
Systemic infection
Uraemia
Neurological conditions -
Cushing's ulcer
Peptic Ulcer disease
Definitions
Ulcer
Full thickness breach in the
mucosa
Erosion
Partial thickness breach in
mucosa
Peptic Ulcer
Defects in the mucosa that penetrate at least into the
submucosa
, secondary to enzymes / acid anywhere in the GI tract
Locations
1st part of duoudenum
Stomach atrum / pre-pyloric
Other - Distal oesophagus, Meckel's diverticulum)
Causes
H. pylori infx
NSAIDs - aspirin
Heavy smoking
Heavy alcohol intake
Corticosteroidis
Hyperacidity incl Zollinger- Ellison syndrome
Complications
Bleeding
Anaemia
Perforation
Scarring -> obstruction
Malignant transformation
Duodenal Peptic Ulcer Pathogenesis
Delivery of excess acid into duoudenum
Induces gastric intestinal metaplasia in duodenum
H. pyloir can infect metaplastic gastric cells
Cell injury, cell death, erosion, ulceration
Pathology by Aeitiology
Congenital
Congenital pyloric stenosis
Aquired
Inflammatory
Acute gastritis
Infection
Helicobacter pylori
Immunological
Autoimmune gastritis
Pre-neoplastic / Neoplastic
Signet ring Adenocarcinoma
GI stromal tumours
Lymphoma
Chronic Gastritis
Definition
Chronic inflammatory changes in the gastric mucosa, eventually leading to the mucosal atrophy / epithelial metaplasia
Types
Type A: Autoimmune Gastritis
Epidemiology
10% of chronic gastritis
Morphology
Fundus and corpus
Associations
Autoimmune conditions eg Hashimoto's
Pernicious anaemia
Pathogenesis
Gland destruction and atrophy
Parietal cell loss
Low secretion of HCL and intrinsic factor
Compensatory high gastrin levels
Low serum B12
Cause
Circulating auto-antibodies against parietal cells and intrinsic factor
Stages
Early
Chronic inflammation
Late
Atropy
Fibrosis
Intestinal metaplasia
Type B: Helicobacter pylori gastritis
Epidemiology
Most common cause of chronic gastritis
90% of duodenal ulcers
70% of gastric ulcers
Morphology
Antrum
Treatment
H. pylori clearance leads to ulcer healing
High recurrence if h. pylori is not cleared
H. pylori
Gram (-) rid
Motile and flagellate
Pathogenesis
H. pylori induces inflammatory and immune response
Tissue injury
VacA
Urease
Phospholipases
Impairs duoudenal bicarb production
Lowers pH in duodenum
Gastric metaplasia develops
Foci for colonisation with h. pylori
Diagnosis
CLO test - Rapid Urease test
Histology
Presentation
Asymptomatic
Pain / nausea
Complications
Gastritis - antral
Peptic ulcer disease
Adenocarcinoma
MALT - mucosa associated lymphoid tissue lymphoma
Type C: Chemical gastritis (NSAIDs, alcohol)
Both Bowels
Inflammatory Bowel Disease - Crohn's
Enterocolitis
Inflammation of the intestines - diarrhoeal disease
Secretory
Increased intestinal fluid secretions
Persists with facting
Caused by cholera + Viral infx
Osmotic
Osmotic retention of fluid in stool
Abates with fasting
Cause
Lactulose therapy
Viral infx
Exudative
Purulent, bloody stools
Persists with fasting
Causes
Infectious : shigeall, salmonella
IBD
Malabsorption
Voluminous bulky stools due to unabsorbed nutrients and excess fat
Stretorrhoea
Abates with fasting
Causes
Coeliac
Giardiasis
Dysmobility
High variably
Must exlude other causes
Causes
IBS
Hyperthyroidism
Infectious Enterocolitis
Viral
Bacterial
Pathogens
C. dif
C. perfringesn
Staph aureus
Cryptosporidium
Shigella
Salmonella
Yersinia
Isachamic Bowel Disease
Presentation
Sudden onset abdominla Pain -VASCULAR IS SUDDEN
+/- Bloody diarrhoea
Rapid
shock
Mortality
Bowel Obstruction
Hernias
Volvulus
Intussueption
Post-Inflammatory Stricture
Adhesions
Intraluminal Objects
Tumour
Pseudo-Obstuction
Large Intestine
Diverticular Disease
Definition
Bling pouch that communicates with the lumen of the gut - outpouching
Causes
Aquired
No / attenuated muscularis propria
Low fibre diet
Decreased stool volum + increased intraluminal pressure
Herniation of bowel wall through anatomical weak points
Congenital
Uncommon
All 3 layers of bowel wall involve
Epidemiology
Age 60
Presentation
Asymptomatic
Bleeding
Diverticulitis
Simple
Complicated
Inflammatory Bowel Disease - Ulcerative Colitis
Catagories
Ulcerative colitis
Features
Coninuous inflammation
Limited to colon and rectum
may have backwash ileitis
Mucosal ulceration
Pseudo-polyps
No mural thickening
Risk of toxic megacolon
Complications
Colorectal carcinoma
Severe Diarrhoea
Electrolyte derangement
Massive
haemorrhage
Toxic megacolon
perforation
periontitis
Extra-intestinal manifestations
Pathology
Diffuse lymphoplasmacytic infiltrate in lamin propria
Acute inflam changes
Crypt abcesses
Ulceration to submucosa only
Chronic inflam
Architectural distortion
Crypt drop out
Dysplasia
Crohn's disease
Features
Transmural inflammation
Mouth-anus
affected
Skip lesions
Fissuring ulceration
Fistula
Creeping fat
Strictures
String sign
Serpentine ulcers
Coalesces into long ulecrs
Cobblestoning
Aphthous ulcers
Erythema and loss of vascular pattern
Complications
Malapsorption
B12
Protein
Fistula formation
Bowel, bladder, vagina, perianal skin
Abdominal abcesses
Intestinal stricture
Obstruction
Massive internal bleeding
Carcinoma
Extra intestinal manifestations
Anterior uveitis
Arthritis
Erythema nodosum
Renal calculi
Histology
Non caseating granulomas
Acute inflammation
Neutrophils forming crypt abscesses
Ulceration
Chronic inflammation
Architectural distortion
Crypt dop out
Dysplasia and malignancy
Definition
Chronic inflammatory disorders with damage to mucosal epithelial barrier and loss of absorptive function
Epidemiology
Bimodal distribution
15-40 yrs
60-70 yrs
Presentation
Chronic relapsing and remitting course
Bloody diarrhoea
Melaena
FEver
Weight loss
Crampy abdo pain
Causes
Genetics
HLA-B27 associated with extra-intestinal features
Failed immune regulation
DEfect in suppressive inflammatory response to normal gut flora
Antigenic triggering by gut microbes
Environmental
Smoking
↑Crohn's risk
↓ UC risk
Hygiene - delayed exposure to antigens
Extra-intestinal Manifestations
MSK
Migratory polyarthritis
Sacroiliitis
Skin
Pyoderma gangrenosum
Erythema nodosum
Sweet syndrome
Aphthous stomatitis
Hepatobiliary
Primary sclerosing choangitis
Autoimmune hepatitis
Eyes
Episcleritis
Anterior uveitis
Iritis
Pathology by Aeitiology
Congenital
Anal anomalies
Atresia
Stenosis
Hirschsprung's disease
Aquired
Infective enteroolitis
Obstruction
Diverticular disease
Rectal mucosal prolapse
Ischaemic bowel disease
Antibiotic ass Pseudomembranous colitis
IBD
Adenoma -> adenocarcinoma
Small Intestine
Malabsorption
Coeliac disease
Definition
Non-infectious cause of malabsorption due to reduction in the absorptive surface area of small intestin
Epidemiology
European / nothern white people
Treatment
Gluten free diet
Presentation
Bloating
Diarrhoea +/- steatorrhoea
Weight loss
Malnutrition
Complications
Short stature
Osteoporosis
Infertility
DErmatitis herpetiformis
Peripheral neuropathy
Headaches
Malignancy - enteropathy associated T cell lymphoma
Associations
Type 1 DM
Autoimmune thyroiditis
Pathological Factors
Environmental
GLuten - protein gliadin
Genetics
HLA-DQ2
HLA-DQ8
Autoantigen
Tissue transglutaminase (tTG)
Diagnosis
Serological tests
Serum tTG-IgA
Serum EMA-IgA
Upper GI endoscopy with D2 biopsy
Gluten withdrawl response
Pathogenesis
Inappropriate immune reaction to gluten derives peptides - gliadin
Gliadin peptides pass through epithelial barrier and are deamidated by tissue transglutaminase (tTG)
tTG modifies gliadin - stimulates immune system
Deamidated gliadin peptides bind to HLA DQ/8 on antigen presenting cells
Peptides presented to CD4+ t-cell - inflammation
Histology
Mucosal inflamation
Villous atrophy
Crypt hyperplasia
Increase in intra-epithelial lymphocytes (IELs)
Small intestinal bacterial overgrowth
Bacterial growth
Suppression
Stomach acidity
Peristaltic activity
IgA
Ileocaecal sphincter
Encouragement
Achlorhydria
Stasis
Stricture
Fistula
Blind loop
Dysmobility
Surgery
Immune defect
Pos surgery loss of ileocaecal valve
Pathogenesis
Inactivation of bile salts by deconjugation - fat malabsorption
Direct inactivation of enzymes
Competition for nutrients
Symptoms
Diarrhoea
Loss of appetite
Nausua
Bloating
Weight loss
Malnutrition
Investigations
Jejunal aspiration
Hydrogen breath test
Treatmetn
Antibiotics
Whipple's disease
Definition
Rare infection with tropheryma whippelii - gram positive bacterium
Symptoms
Systemic infection
Intestines
CNS
Joints
Minimal if any inflammatory reaction
Histology
PAS positive for macrophages in lamina propria
Treatmet
Antibiotics
Tropical Sprue
Cause
Idiopathic
Presumed post infex
Symptoms
Similar to coeliac
Epidemiology
People visiting tropics
Presentation
Acute diarrhoea
Malabsorption
Villous blunting within days -weeks
Giardia
Protozoa
Pathogenesis
Ingestion of giardia as dormant cyst in water
Colonisses and proliferates in small intestine
Remains in lumen
Path of malapsorption uncertain
Abetalipoproteinaemia
Definition
Rare genetic inability to synthesize apolopoprotein B - required for assembly of dietary lipids into chylomicrons
Presentation
Steatorrhoe
Failure to thrive in infancy
Features
DEfective synthesis of chylomicrons
Defect in export of fat from enterocyte
Presentaition
Diarrhoes
Steatorrhoea
Nutrient deficiencies
Failure to thrive
Wieght loss
Short stature
Fat soluble vit deficiencies
Iron deficiency
Phases of Digestion
Intraluminal Digestion
Pancreatic insufficiency
Chornic pancreatitis
Cystic fibrosis
Crohn's
Bacterial overgrowth
Cholestatic liver disease
Surgical resection
Mucosal Absorption
Coeliac
Tropical sprue
Whipple's diease
Crohn's
Post small bowel resection
Giardia infestation
Nutrient delivery
Lymphatic blockage
Primary lymphangiectasia
Lymphatic obstruction
Meckel's Diverticulum
Definition
Congenital outpoching in small bowel arising from incomplete obliteration of embryonic vitelline duct
Complications
Acute abdomen
Peptic ulceration in gastic mucosa
Bleeding
Perforation
Abcess formation
Obstruction
Rule of 2'
2% of people
2ft proximal from ileo-caecal valve
2in length
