Gastrointestinal Flashcards
What is considered to be an upper GI bleed?
- Bleeding above the duodenum
What are the causes of upper GI bleeds?
- oesophageal varices
- Mallory-Weiss tear (tear of oesophageal mucous membrane)
- ulcers or cancers of stomach and duodenum
What are the 1st and 2nd line drugs for oesophageal varices?
- IV terlipressin
- IV somatostatin (CI due to IHD)
What is the presentation of GI bleeds?
- haematemesis
- coffee ground vomit
- melaenea
- haemodynamic instability occurs in large blood loss and leads to low BP
How can you tell (from their bloods) if a patient is bleeding?
- low Hb and high urea from breakdown products
How are upper GI bleeds investigated?
- Bloods: Hb, urea, coagulation (INR, FBC), LFTs and crossmatch
How are upper GI bleeds managed (ABATEDO)?
- ABCDE approach
- Bloods
- Access
- Transfuse: blood, platelets, clotting factors, prothrombin
- Endoscopy
- Drugs
- OGD to cauterise bleeds
What are some causes of intraluminal obstruction?
- tumour: carcinoma or lymphoma
- diaphragm disease
- meconium ileus
- gallstone ileus
What are some causes of intramural obstruction?
- inflammatory: Crohn’s disease, diverticulitis
- tumours
- neural: Hirschsprung’s disease
What are the causes of extraluminal obstruction?
- adhesions
- volvulus: occurs in sigmoid colon as it’s not fixed
- tumour
What is small bowel obstruction?
- a mechanical blockage of the bowel
- from within or outside the lumen
- form of intestinal failure
- inability of gut to absorb necessary water, macronutrients and electrolytes
- requires IV supplementation or replacement
What is the aetiology of small bowel obstruction?
- adhesions
- hernia (bulges)
- cancer
How do adhesions cause obstruction?
- fibrous bands of scar tissue
- cause kinking or squeezing of bowel
- occurs due to surgery, peritonitis, infection or endometriosis
- occurs in small bowel more than large
How do cancers cause obstruction?
- primary tumours can be surgically removed
- secondary difficult to remove and can encase bowel
- local tumour or tumour spread
- single or multilevel
How does bowel obstruction present?
- green bilious vomiting
- abdo distention
- tinkling bowel sounds
- constipation and lack of flatulence
How can you tell the difference between small and large bowel obstruction?
- small presents with vomiting early on, before constipation
- large presents with constipation and late onset vomiting
How do you take a history for small bowel obstruction?
- colic
- bloating/distention
- sudden vs gradual onset
- bilious vomiting
- ask about previous surgery, last eat and drink
- medical comorbidities
Which investigations are used for small bowel obstruction?
- FBC: shows anaemia if cancer
- U&E
- Lactate raised - bowel ischaemia
- X-ray: distended loops of bowel
- metabolic alkalosis
- CT: gold
Why is contrast CT useful for small bowel obstruction?
- localises site of obstruction
- indicates the cause
- tells you if bowel is ischaemic and if intervention is required immediately
How is small bowel obstruction treated?
- IV analgesia for pain
- antiemetics
- nutrition: may need parenteral feed
What is the most common complication of small bowel obstruction?
- renal failure
What is the epithelium lining the oesophagus and the stomach?
- oesophagus: squamous
- stomach: columnar with glands covered with mucus
- acid refluxed up into oesophagus kills squamous cells leading to gap at junction
- leads to Barrett’s oesophagus
What is Gastro-oesophageal reflux disease?
- dysfunction of the lower oesophageal sphincter
- allows acid reflux
- irritates sensitive squamous lining of oesophagus
How does GORD present?
- heartburn: related to meals, lying down, strain
- nocturnal asthma
- acid/bile regurgitation
- bloating
- odynophagia (painful swallowing)
How is GORD investigated and what are the criteria?
- endoscopy
- over 55
- symptoms lasting 4+ weeks
- dysphagia
- weight loss
- indigestion despite treatment
What are the possible causes of GORD?
- smoking
- alcohol
- hiatus hernia
- pregnancy
- obesity
- big meals
- tricyclics/anticholinergics/nitrates
What is the lifestyle advice given for GORD?
- weight loss
- small regular meals
- avoid alcohol, hot drinks, eating before bed
- stay upright after meals
How is GORD managed (drugs and surgery)?
- antacids
- alginates (Gaviscon)
- PPIs: omeprazole, lansoprazole
- surgery: laparoscopic fundoplication
- Barrett’s oesophagus:
- what is it
- what is it a risk factor for
- how is it treated?
- metaplasia from squamous to columnar epithelium
- premalignant RF for adenocarcinoma, monitored by endoscopy
- treated by PPIs
- ablation treatment (laser, cryotherapy) prevents progression to cancer
What are the typical characteristics of Crohn’s (NESTS)
- No blood or mucus
- Entire GI tract (mainly ileum)
- Skip lesions: unaffected areas between active disease
- Terminal ileum (and proximal colon) most affected with transmural inflammation
- Smoking is a risk factor
What are the characteristics of ulcerative colitis (CLOSE)?
- continuous inflammation
- limited to colon and rectum
- only superficial mucosa affected
- smoking is protective
- excreted blood and mucus
What is the pathophysiology of IBD?
- develops as a result of environmental trigger in genetically susceptible individual
- bacteria or dietary antigens taken up by M cells, pass through gap between cells
- picked up by antigen presenting cells causing secretion of pro-inflammatory cytokines
- activates T cells leading to inflammation
How does IBD present?
- diarrhoea
- abdominal pain
- passing blood
- weight loss
- clubbing
- erythema nodosum
What are some specific features of the presentation of ulcerative colitis?
- blood and mucus with gradual onset of diarrhoea
- bowel frequency related to severity of disease
- crampy abdominal discomfort
How is IBD investigated?
- bloods: anaemia, FBC, U&Es, cultures
- CRP: inflammation and active disease
- faecal calprotectin
- endoscopy
- imaging for complications
How is ulcerative colitis managed?
inducing remission:
- 1st line: aminosalocylate (mesalazine)
- 2nd line: corticosteroids: prednisolone
- hydrocortisone ± cyclosporin if severe
- maintaining remission: sulfasalazine, mesalazine
- surgery: can remove colon > ileostomy pouch
How is Crohn’s managed?
- inducing remission: steroids: prednisolone
- hydrocortisone if severe
- maintaining remission: azathioprine, methotrexate
- surgery: can resect distal ileum, strictures and fistulas
What is irritable bowel syndrome?
- functional bowel disorder
- symptoms resulting from abnormal functioning of bowel
- due to disorders of gut motility or brain-gut axis
What are the symptoms of IBS?
- fluctuating bowel habit: alternating constipation and diarrhoea
- abdominal pain relieved by defecation
- bloating
- chronic and exacerbated by stress
How is IBS diagnosed?
- exclusion: bloods, faecal calprotectin (IBD), anti-TTG (coeliac), colonoscopy
- abdo pain + 2 symptoms
How is IBS managed?
- try exclusion diets
- reduced processed food, caffeine and alcohol
- regular small meals and fluid
- loperamide for diarrhoea
- laxatives for constipation
- tricyclic antidepressants, SSRIs
What is the pathophysiology behind coeliac disease?
- T-cell mediated: auto-antibodies created in response to gluten exposure, targeting epithelial cells
- anti-tissue transglutaminase and anti-endomysial (IgA)
- affects small bowel, particularly jejunum, causing villus atrophy and malabsorption
How does coeliac disease present?
- fatigue
- diarrhoea
- weigh loss
- anaemia secondary to iron, B12, folate deficiency
- dermatitis herpetiformis
- failure to thrive (children)
How is coeliac disease diagnosed and managed?
- check IgA levels
- raised anti-TTG or anti-endomysial
- endoscopy: crypt hypertrophy and villous atrophy
- management: lifelong gluten-free diet
Which conditions is coeliac disease associated with?
- T1DM
- thyroid disease
- autoimmune hepatitis
- primary biliary cirrhosis, primary sclerosing cholangitis
- HLA-DQ2 gene
What is gastritis and what are the causes?
- gastric mucosal inflammation
- caused by H. pylori, NSAIDs, alcohol use, bile reflex, stress
What are the symptoms of gastritis?
- nausea, vomiting
- loss of appetite
- dyspepsia/epigastric discomfort
How is gastritis investigated?
- H. pylori urea breath test
- H. pylori faecal antigen test
- FBC
- endoscopy
What is the anatomy of the appendix and epidemiology of appendicitis?
- small, thin tube arising from caecum, leads to dead end
- located where 3 teniae coli meet
- patients aged 10-20
What is the pathophysiology behind appendicitis?
- pathogens trapped due to obstruction where the appendix meets the bowel
- trapped pathogens > infection + inflammation
- can lead to gangrene and rupture > faeces and infectious material released into peritoneum
- leads to peritonitis
What is the presentation of appendicitis?
- central abdo pain > R iliac fossa
- tenderness at McBurney’s point on palpation
- loss of appetite
- guarding
- rebound and percussion tenderness
How is appendicitis diagnosed?
- clinical presentation
- raised inflammatory markers
- CT/ultrasound
- potential diagnostic laparoscopy
What are the key differential diagnoses of appendicitis?
- ovarian cysts
- Meckel’s diverticulum
- ectopic pregnancy (hCG to exclude)
How is appendicitis managed?
- appendectomy
- laparoscopic surgery is ideal over open
What is the pathophysiology behind peptic ulcers?
- occurs from breakdown of protective mucosal layer or inc in stomach acid
- broken down by medications, H, pylori
- stomach acid inc by: stress, alcohol, caffeine, smoking, spicy food
- duodenal more common than gastric
How do peptic ulcers present?
- epigastric discomfort/pain
- nausea and vomiting
- dyspepsia
- coffee ground vomiting and melaena
- iron deficiency anaemia
How are peptic ulcers diagnosed and managed?
- endoscopy and biopsy to exclude cancer
- high dose PPIs
What are the complications of peptic ulcers?
- bleeding
- perforation
- scarring and strictures leading to pyloric stenosis
What are the diverticula?
- pouch or pocket in the bowel wall ranging between 0.5-1cm
- diverticulosis: presence of diverticula without inflammation/infection
What is the difference between diverticulosis, diverticular disease and diverticulitis?
- diverticulosis: presence of diverticula without inflammation/infection
- diverticular disease: when patients experience symptoms
- diverticulitis: inflammation and infection of diverticula
What is the pathophysiology behind diverticular disease?
- small intestine contains circular muscle which is weaker in areas where it is penetrated by blood vessles
- inc pressure in lumen over time causes gaps allowing mucosa to herniate and diverticula formation
- diverticula don’t form in rectum due to teniae coli
- lack of dietary fibre inc risk
Describe diverticulosis (definition, causes)
- wear and tear of bowel
- mostly affects sigmoid colon
- common with inc age, low fibre diet, obesity, NSAIDs
How is diverticulosis diagnosed and managed?
- colonoscopy or CT
- advice: high fibre diet and weight loss
- bulk forming laxatives, surgery if serious
- avoid stimulant laxatives
How does acute diverticulitis present?
- pain in left iliac fossa
- fever
- diarrhoea, nausea, vomiting
- rectal bleeding
- raised inflammatory markers and WBC
How is acute diverticulitis treated?
- oral co-amoxiclav
- analgesia
- only clear liquids until symptoms improve
- may need surgery
What are the types of oesophageal cancer?
- Adenocarcinoma: lower 1/3 of oesophagus, is associated with Barret’s oesophagus
- squamous cell carcinoma: smoking, alcohol, hot fluids, upper 2/3 of oesophagus
How does oesophageal cancer present?
- lymphadenopathy
- vocal cord paralysis
- melaena
- dysphagia, regurgitation, heartburn, hoarseness
How is oesophageal cancer investigated and managed?
- OGD and biopsy
- chemotherapy/radiotherapy, surgery
What are the types and causes of gastric carcinomas?
- mostly adenocarcinomas
- H. pylori
- smoking
- CDH-1 mutation
- pernicious anaemia
What is chronic mesenteric ischaemia?
- caused by a lack of blood flow due to atherosclerosis through the mesenteric vessels resulting in ischaemia
How does mesenteric ischaemia present?
- central, colicky abdo pain after eating
- weight loss due to food avoidance
- abdo bruit on auscultation
How is mesenteric ischaemia diagnosed and managed?
- CT angiography
- reduce modifiable risk factors
- 2º prevention: statins, antiplatelets
- revascularisation: endovascular procedure
What is the pathophysiology behind acute mesenteric ischaemia?
- rapid blockage in blood flow through superior mesenteric artery
- caused by thrombus blocking blood flow
- AF causes clot to travel LA > aorta > SMA
How is acute mesenteric ischaemia diagnosed?
- presentation with acute, non-specific abdo pain
- contrast CT
- metabolic acidosis and raised lactate levels
What is ischaemic colitis?
- most common ischaemic bowel disease
- lack of blood flow to colon
- splenic flexure most commonly affected
- rectum is resistant due to dual supply from IMA and int iliac.
What is the pathophysiology behind pancreatic cancer?
- majority adenocarcinomas
- mostly occur in head of pancreas
- leads to obstructive jaundice
- also presents with new onset or worsening T2DM
What is the Whipple procedure?
- pancreaticoduocenectomy
- removal of: head of pancreas, pylorus of stomach, duodenum, gallbladder, bile duct, relevant lymph nodes
What investigations can be done in pancreatic cancer?
- staging CT (CT TAP)
- CA 19-9: tumour marker: may be raised in pancreatic cancer
- MCRP or ERCP
What are the features of an abdominal wall hernia?
- soft lump protruding from abdo wall
- may be reducible or protrude on coughing
- aching, pulling or dragging sensation
What is a hiatus hernia?
- herniation of stomach up through the diaphragm
- contents of stomach reflux into oesophagus
What are the symptoms of hiatus hernias?
- heartburn
- acid or food reflux
- burping and bloating
- halitosis
How are hernias investigated?
- CXR
- CT
- endoscopy
- barium swallow
What are the complications of hernias?
- incarceration: irreducible into proper position
- obstruction: causes blockage of passage of faeces through bowel
- strangulation: non-deductible and causes ischaemia of bowel
What is the general management of hernias?
- conservative management
- tension-free repair: placing a mesh over the defect
- tension repair: suturing muscle and tissue
What is gastroenteritis?
- inflammation from the stomach through to the intestines presenting with nausea, vomiting and diarrhoea
What is an indirect inguinal hernia?
- bowel herniates through inguinal canal
- IIHs remain reduced when pressure is applied to the deep inguinal ring
What is a direct inguinal hernia?
- occurs due to weakness at Hesselbach’s triangle
- boundaries: rectus abdominus (medial), inferior epigastric vessels (superior/lateral border), Poupart’s ligament
What are the most common causes of viral gastroenteritis?
- rotavirus
- norovirus
- adenovirus
Which bacteria commonly causes gastroenteritis?
- E. coli
- campylobacter jejuni
- shigella
- bacillus cereus
How does E. coli spread?
- through infected faeces, unwashed salad, water
What toxin does E. coli produce and what symptoms does this lead to?
- shiga toxin
- abdo cramps, bloody diarrhoea and vomiting
- destroys blood cells > haemolytic uraemia syndrome
What type of bacteria is campylobacter jejuni and how is it spread?
- causes travellers diarrhoea
- gram negative curved/spiral bacteria
- raw/improperly cooked poultry, untreated water, unpasteurised milk
What are the symptoms and treatment of campylobacter jejuni infection?
- abdo cramps, bloody diarrhoea, vomiting, fever
- azithromycin and ciprofloxacin
How does shigella spread and what are the symptoms?
- faeces contaminating drinking water, pools and food
- abdo cramps, bloody diarrhoea, fever
- shiga toxin > haemolytic uraemia syndrome
How is salmonella spread and what are the symptoms?
- raw eggs and poultry
- water diarrhoea with mucus/blood, abdo pain and vomiting
What type of bacteria is bacillus cereus and on what food is it produced?
- gram positive rod
- inadequately cooked food/food not immediately refrigerated
- fried rice
What toxin does bacillus cereus produce and what symptoms does it cause?
- cereulide
- abdo cramping, vomiting and water diarrhoea
What is giardiasis, what are the symptoms and how is it treated?
- Giardia lamblia is a microscopic parasite spread by faeco-oral transmission
- can be asymptomatic or cause chronic diarrhoea
- treated with metronidazole
How is gastroenteritis managed?
- isolation, barrier nursing, infection control
- microscopy, culture and sensitivities
- fluid challenge and rehydration
What is the presentation of malabsorption?
- diarrhoea
- weight loss
- lethargy
- steatorrhoea
What are the investigations for malabsorption?
- FBC
- dec Ca, Fe, B12, folate
- Sudan for fat globules
What is Meckel’s diverticulum?
- congenital outpouching of small bowel
- GI bleeding, obstructive symptoms
- leads to volvulus and intussusception
