3.03 General Surgery - Small Bowel Disease Flashcards
What is angiodysplasia?
A vascular abnormality of the gastrointestinal tract, caused by the formation of arteriovenous malformations between previously healthy blood vessels.
Where in the GI tract does angiodysplasia most commonly affect?
- caecum
- ascending colon
Describe the pathophysiology of:
a) acquired angiodysplasia
b) congenital angiodysplasia
a) chronic and intermittent contraction of the colon reduces submucosal venous drainage, giving rise to dilated and tortuous veins. This results in the loss of pre-capillary sphincter competency and forms small arteriovenous communications, characterised by a small tuft of dilated vessels.
b) causes include hereditary haemorrhagic telangectasia
What are the clinical features of angiodysplasia?
- rectal bleeding
- anaemia
In severe cases, acute haemorrhage can occur.
How is angiodysplasia investigated?
- blood tests (FBC, U&Es, LFTs, clotting)
- ODG / colonoscopy to exclude malignancy
- mesenteric angiography to locate and plan intervention
How is angiodysplasia managed?
Endoscopic argon plasma exposure.
Bowel resection if:
- continuation of severe bleeding despite endoscopic management
- severe acute life-threatening GI bleed
- multiple angiodysplastic lesions identified
What are the complications of angiodysplasia?
Around 15% of patients will have severe haemorrhage.
What is gastroenteritis?
Inflammation of the gastrointestinal tract, usually considered infective in origin.
Differences in the length of time between ingestion of food and development of symptoms can often reveal the causative agent.
Give the symptom onset expected if gastroenteritis is of:
a) bacterial toxins cause
b) viral cause
c) bacterial cause
d) parasitic cause
a) hours
b) days
c) weeks
d) months
Define:
a) diarrhoea
b) acute diarrhoea
c) chronic diarrhoea
d) dysentery
e) travellers’ diarrhoea
a) 3 or more loose stools or stools with increased liquid per day.
b) lasting less than 14 days
c) lasting longer than 14 days
d) gastroenteritis characterised by loose stools with blood and mucus
e) more than 3 loose stools within 24 hours of foreign travel, with or without cramps, nausea, fever, or vomiting.
What are the risk factors for gastroenteritis?
- poor food preparation
- immunocompromised
- poor personal hygiene
What are the clinical features of gastroenteritis?
- cramp-like abdominal pain
- diarrhoea (+/- blood or mucus)
- vomiting
- night sweats
- weight loss
OE dehydration and pyrexia
What specific questions should be asked when taking a history from a patient with diarrhoea?
- bowel movements (blood, mucus, watery)
- affected friends or family
- recent travel abroad
- recent use of antibiotics*
*can suggest potential C. difficile infection
How is gastroenteritis managed?
- rehydration, encouraging oral intake where possible
- education to prevent future episodes
- exclusion from work / school until 48hrs from last episode of vomiting or diarrhoea
Give some possible viral causes of gastroenteritis and discuss how they may present.
- Norovirus: most common form of viral gastroenteritis in adults, presenting with abdominal pain, watery diarrhoea and vomiting. Typically resolves within 1-3 days.
- Rotavirus: results in severe diarrhoea among infants and young children. Typically resolves within 1 week.
- Adenovirus: common cause of diarrhoea in children.
Give some possible bacterial causes of gastroenteritis and discuss how they may present.
- Campylobacter: a Gram -ve bacillus being the most common cause of food poisoning, presenting with a prodrome of fatigue, fever or myalgia, followed by nausea, abdominal cramps and diarrhoea.
- E. coli: a Gram -ve bacillus, transmitted through contaminated food. Enterotoxigenic E. coli is the most common cause of Traveller’s diarrhoea.
- Salmonella: a Gram -ve bacillus, transmitted through undercooked poultry or raw eggs; presents with fever, vomiting, abdominal cramps and bloody diarrhoea.
- Shigella: a Gram -ve bacillus, acquired from contaminated dairy products and water; presents with fever, abdominal pain or bloody diarrhoea.
Give some possible bacterial toxin causes of gastroenteritis and discuss how they may present.
- Staphylococcus aureus: found in meat and dairy products; even re-heating the food does not destroy the exotoxin.
- Bacillus cereus: usually found in reheated rice; causes rapid-onset vomiting and abdominal cramps.
- Clostridium perfringes: usually found in reheated meat dishes; causes diarrhoea and less commonly vomiting.
- Vibrio cholera: usually found in contaminated water supplies; causes profound watery painless diarrhoea.
Give some possible parasitic causes of gastroenteritis and discuss how they may present.
Parasites are most common cause of Traveller’s diarrhoea.
- Cryptosporidium: causes a self-limiting watery diarrhoea and abdominal cramps; diagnosis made with stool culture for ova, cysts and parasites.
- Entamoeba histolytica: anaerobic parasite acquired from faecally-contaminated food or water; presents with bloody diarrhoea, abdominal pain and fever. Diagnosis made with stol culture for ova, cysts and parasites. Treated with metronidazole.
- Giardia intestinalis: transmitted through direct contact or faeco-oral route; causes acute disease (diarrhoea, fever, fatigue, nausea and bloating) or chronic disease (steatorrhoea, malabsorption, weight loss). Diagnosis by stool culture for ova, cysts and parasites. Treated with metronidazole.
- Schistosoma: acute schistosomiasis develops around a month after infection from contaminated water; presents with fever, malaise, abdominal pain, bloody diarrhoea. In severe cases can cause chronic liver disease.
What are the complications of C. difficile gastroenteritis?
Potentially develops into toxic megacolon if not prompty treated with oral metronidazole or vancomycin.
Severely dilated bowel with high risk of perforation.
