Gastroenterology Flashcards
What are the causes of diarrhoea?
-
Acute
- Suspect gastroenteritis
- Travel, diet, contacts?
-
Chronic
- Diarrhoea alternating with constipation: IBS
- Anorexia, ↓wt., nocturnal diarrhoea: organic cause
-
Bloody
- Vascular: ischaemic colitis
- Infective: campylobacter, shigella, salmonella, E. coli, amoeba, pseudomembranous colitis
- Inflammatory: UC, Crohn’s
- Neoplastic: CRC, polyps
-
Mucus
- IBS, CRC, polyps
-
Pus
- IBD, diverticulitis, abscess
-
Assoc. c¯ medical disease
- ↑ T4
- Autonomic neuropathy (e.g. DM)
- Carcinoid
-
Assoc. c¯ drugs
- Abx
- PPI, cimetidine
- NSAIDs
- Digoxin
What investigations would you perform in a patient presenting with diarrhoea?
-
Bloods
- FBC: ↑ WCC, anaemia
- U+E: ↓K+, dehydration
- ↑ESR: IBD, Ca
- ↑CRP: IBD, infection
- Coeliac serology: anti-TTG or anti-endomysial Abs
-
Stool
- MCS and C. diff toxin
How would you manage a patient with diarrhoea?
- Treat cause
- Oral or IV rehydration
- Codeine phosphate or loperamide after each loose stool
- Anti-emetic if assoc. with n/v: e.g. prochlorperazine
- Abx (e.g. cipro) in infective diarrhoea → systemic illness
What is the pathogen, epidemiology and risk factors for C. diff diarrhoea?
Pathogen
- Gm+ve spore-forming anaerobe
- Release enterotoxins A and B
- Spores are v. robust and can survive for >40d
Epidemiology
- Commonest cause (25%) of Abx assoc. diarrhoea
- 100% of Abx assoc. pseudomembranous colitis
- Stool carriage in 3% of healthy adults and 15-30% of hospital pts.
Risk Factors
- Abx: e.g. clindamycin, cefs, augmentin, quinolones
- ↑ age
- In hospital: ↑ c¯ length of stay, ↑ c¯ C. diff +ve contact
- PPIs
How can C. diff infection present?
- Asymptomatic
- Mild diarrhoea
- Colitis w/o pseudomembranes
- Pseudomembranous colitis
- Fulminant colitis
- May occur up to 2mo after discontinuation of Abx
What are the features of Pseudomembranous Colitis?
- Severe systemic symptoms: fever, dehydration
- Abdominal pain, bloody diarrhoea, mucus PR
- Pseudomembranes (yellow plaques) on flexi sig
- Complications
- Paralytic ileus
- Toxic dilatation → perforation
- Multi-organ failure
What investigations would you perform in a patient presenting with suspected C. diff?
- Bloods: ↑↑CRP, ↑↑WCC, ↓albumin, dehydration
- CDT ELISA
- Stool culture
What markers of severe disease are there for C. diff infection?
Severe Disease: ≥1 of
- WCC >15
- Cr >50% above baseline
- Temp >38.5
- Clinical / radiological evidence of severe colitis
How would you manage a patient with C. diff infection?
General
- Stop causative Abx
- Avoid antidiarrhoeals and opiates
- Enteric precautions
Specific
- 1st line: Metronidazole 400mg TDS PO x 10-14d
-
2nd line: Vanc 125mg QDS PO x 10-14d
- Failed metro
-
Severe: Vanc 1st (may add metro IV)
- ↑ to 250mg QDS if no response (max 500mg)
- Urgent colectomy may be needed if
- Toxic megacolon
- ↑ LDH
- Deteriorating condition
-
Recurrence (15-30%)
- Reinfection or residual spores
- Repeat course of metro x 10-14d
- Vanc if further relapse (25%)
What are the causes of constipation?
OPENED IT
-
Obstruction
- Mechanical: adhesions, hernia, Ca, inflamatory strictures, pelvic mass
- Pseudo-obstruction: post-op ileus
-
Pain
- Anal fissure
- Proctalgia fugax
-
Endocrine / Electrolytes
- Endo: ↓T4
- Electrolytes: ↓Ca, ↓K, uraemia
-
Neuro
- MS
- Myelopathy
- Cauda equina syndrome
- Elderly
- Diet / Dehydration
- IBS
-
Toxins
- Opioids
- Anti-mACh
How would you manage a patient with constipation?
-
General
- Drink more
- ↑ dietary fibre
-
Bulking: ↑ faecal mass → ↑ peristalsis
- CI: obstruction and faecal impaction
- Bran
- Ispaghula husk (Fybogel)
- Methylcellulose
-
Osmotic: retain fluid in the bowel
- Lactulose
- MgSO4 (rapid)
-
Stimulant: ↑ intestinal motility and secretion
- CI: obstruction, acute colitis
- SE: abdo cramps
- Bisacodyl PO or PR
- Senna
- Docusate sodium
- Sodium picosulphate (rapid)
-
Softeners
- Useful when managing painful anal conditions
- Liquid paraffin
-
Enemas
- Phosphate enema (osmotic)
-
Suppositories
- Glycerol (stimulant)
What is the definition of IBS?
Disorders of enhanced visceral perception → bowel symptoms for which no organic cause can be found
What are the diagnostic criteria for IBS?
ROME Criteria
- Abdo discomfort / pain for ≥ 12wks which has 2 of:
- Relieved by defecation
- Change in stool frequency (D or C)
- Change in stool form: pellets, mucus
- 2 of:
- Urgency
- Incomplete evacuation
- Abdo bloating / distension
- Mucous PR
- Worsening symptoms after food
- 2 of:
-
Exclusion criteria
- >40yrs
- Bloody stool
- Anorexia
- Wt. loss
- Diarrhoea at night
How would you investigate and manage a patient with IBS?
Investigations
- Bloods: FBC, ESR, LFT, coeliac serology, TSH
- Colonoscopy: if >60yrs or any features of organic disease
Management
- Exclusion diets can be tried
- Bulking agents for constipation and diarrhoea (e.g.
- fybogel).
- Antispasmodics for colic/bloating (e.g. mebeverine)
- Amitriptyline may be helpful
- CBT
What are the causes of dysphagia?
-
Inflammatory
- Tonsillitis, pharyngitis
- Oesophagitis: GORD, candida
- Oral candidiasis
- Aphthous ulcers
-
Mechanical Block
-
Luminal
- FB
- Large food bolus
-
Mural
- Benign stricture
- Web (e.g. Plummer-Vinson)
- Oesophagitis
- Trauma (e.g. OGD)
- Malignant stricture
- Pharynx, oesophagus, gastric
- Pharyngeal pouch
- Benign stricture
-
Extra-mural
- Lung Ca
- Rolling hiatus hernia
- Mediastinal LNs (e.g. lymphoma)
- Retrosternal goitre
- Thoracic aortic aneurysm
-
Luminal
-
Motility Disorders
-
Local
- Achalasia
- Diffuse oesophageal spasm
- Nutcracker oesophagus
- Bulbar / pseudobulbar palsy (CVA, MND)
-
Systemic
- Systemic sclerosis / CREST
- MG
-
Local
What are the different ways in which dysphagia can present?
- Dysphagia for liquids and solids at start
- Yes: motility disorder
- No, solids > liquids: stricture
- Difficulty making swallowing movement: bulbar palsy
- Odonophagia: Ca, oesophageal ulcer, spasm
- Intermittent: oesophageal spasm
- Constant and worsening: malignant stricture
- Neck bulges or gurgles on drinking: pharyngeal pouch
What clinical signs would you look for when examining a patient with dysphagia?
- Cachexia
- Anaemia
- Virchow’s node (+ve = Troisier’s sign)
- Neurology
- Signs of systemic disease (e.g. scleroderma)
What investigations would you like to perform in a patient with dysphagia?
- Bloods: FBC, U+E
- CXR
- OGD
- Barium swallow ± video fluoroscopy
- Oesophageal manometrry
What is the pathophysiology, cause, presentation and complication of achalasia?
-
Pathophysiology
- Degeneration of myenteric plexus (Auerbach’s)
- ↓ peristalsis
- LOS fails to relax
-
Cause
- 1O / idiopathic: commonest
- 2O: oesophageal Ca, Chagas’ disease (T. cruzii)
-
Presentation
- Dysphagia: liquids and solids at same time
- Regurgitation
- Substernal cramps
- Wt. loss
-
Comps
- Chronic achalasia → oesophageal SCC
How would you investigate and manage a patient with achalasia?
-
Investigations
- Ba swallow: dilated tapering oesophagus (Bird’s beak)
- Manometry: failure of relaxation + ↓ peristalsis
- CXR: may show widended mediastinum
- OGD: exclude malignancy
-
Management
- Med: CCBs, nitrates
- Int: endoscopic balloon dilatation, botulinum toxin injection
- Surg: Heller’s cardiomyotomy (open or endo)
What should you know about a pharyngeal pouch?
AKA Zenker’s Diverticulum
- Outpouching of oesophagus between upper boarder of cricopharyngeus muscle and lower boarder of inferior constrictor of pharynx
- Weak area called Killian’s dehiscence.
- Defect usually occurs posteriorly but swelling usually bulges to left side of neck.
- Food debris → pouch expansion → oesophageal compression → dysphagia.
- Pres: regurgitation, halitosis, gurgling sounds
- Rx: excision, endoscopic stapling
What is diffuse oesophageal spasm?
- Intermittent dysphagia ± chest pain
- Ba swallow shows corkscrew oesophagus
What is nutcracker oesophagus?
↑ contraction pressure with normal peristalsis
What worrying associated features might there be with dyspepsia?
ALARM Symptoms
- Anaemia
- Loss of wt.
- Anorexia
- Recent onset progressive symptoms
- Melaena or haematemesis
- Swallowing difficulty
What are the causes of dyspepsia?
- Inflammation: GORD, gastritis, PUD
- Ca: oesophageal, gastric
- Functional: non-ulcer dyspepsia
How would you manage a patient with new onset dyspepsia?
- OGD if >55 or ALARMS
- Try conservative measures for 4 wks
- Stop drugs: NSAIDs, CCBs (relax LOS)
- Lose wt., stop smoking, ↓ EtOH
- Avoid hot drinks and spicy food
- OTC
- Antacids: magnesium trisilicate
- Alginates: gaviscon advance
- Test for H. pylori if no improvement: breath or serology
- +ve → eradication therapy
- Consider OGD if no improvement
- -ve → PPI trial for 4wks
- Consider OGD if no improvement
- PPIs can be used intermittently to control symptoms.
- +ve → eradication therapy
-
Proven GORD
- Full dose PPI for 1-2mo
- Then, low-dose PPI PRN
-
Proven PUD
- Full dose PPI for 1-2mo
- H. pylori eradication if positive
- Endoscopy to check for resolution if GU
- Then, low-dose PPI PRN
What is H. pylori eradication therapy?
- 7 days Rx
- NB. PPIs and cimetidine → false –ve C13 breath tests and antigen tests so stop >2wks before.
- PAC 500
- PPI: lansoprazole 30mg BD
- Amoxicillin 1g BD
- Clarithromycin 500mg BD
- PMC 250
- PPI: lansoprazole 30mg BD
- Metronidazole 400mg BD
- Clarithromycin 250mg BD
- Failure
- 95% success
- Mostly due to poor compliance
- Add bismuth
- Stools become tarry black
What are the causes of peptic ulcer disease?
- Acute: usually due to drugs (NSAIDs, steroids) or “stress”
- Chronic: drugs, H. pylori, ↑Ca, Zollinger-Ellison
What are the features of duodenal ulcers?
- Pathology
- 4x commoner than GU
- 1st part of duodenum (cap)
- M>F
- Risk factors
- H. pylori (90%)
- Drugs: NSAIDs, steroids
- Smoking
- EtOH
- ↑ gastric emptying
- Blood group O
- Presentation
- Epigastric pain:
- Before meals and at night
- Relieved by eating or milk
- Epigastric pain:
What are the features of gastric ulcers?
- Pathology
- Lesser curve of gastric antrum
- Beware ulcers elsewhere (often malignant)
- Risk factors
- H. pylori (80%)
- Smoking
- Drugs
- Delayed gastric emptying
- Stress
- Cushing’s: intracranial disease
- Curling’s: burns, sepsis, trauma
- Presentation
- Epigastric pain:
- Worse on eating
- Relieved by antacids
- Wt. loss
- Epigastric pain:
What are the complications of peptic ulcer disease?
-
Haemorrhage
- Haematemeis or melaena
- Fe deficiency anaemia
-
Perforation
- Peritonitis
-
Gastric Outflow Obstruction
- Vomiting, colic, distension
-
Malignancy
- ↑ risk c¯ H. pylori
How would you investigate a patient with peptic ulcer disease?
- Bloods: FBC, urea (↑ in haemorrhage)
- C13 breath test
- OGD (stop PPIs >2wks before)
- CLO / urease test for H. pylori
- Always take biopsies of ulcers to check for Ca
- Gastrin levels if Zollinger-Ellison suspected