Small Bowel Flashcards
What is a hernia?
an abnormal protrusion of a viscus outwith its normal body cavity
What are predisposing factors for hernias?
coughing constipation pregnancy obesity heavy lifting
What are the different types of hernia?
hiatus incisional epigastric obturator paraumbilical umbilical femoral inguinal (direct or indirect)
What is an incisional hernia?
protrusion of contents of cavity through an incision (after operation) - usually abdo surgery
structurally weakened anterior abdo wall
What is a paraumbilical hernia?
through linea alba (around umbilical region - not umbilicus itself)
What is an umbilical hernia?
congenital
- omphalocele
- gastroschisis
operate if not resolved by 3 years
What is an obturator hernia?
hernia of pelvic floor through obturator foramen into obturator canal
How does an obturator hernia present?
mass in medial upper thigh, symptoms of bowel obstruction?
What are the differences between a direct and an indirect inguinal hernia?
indirect - bowel enters canal via deep inguinal ring, lateral to inferior epigastric vessels, controlled by digital pressure over internal/deep inguinal ring when patient coughs
direct - weakness in posterior wall of canal (transversalis fascia), medial to inferior epigastric vessels, poorly controlled by digital pressure over deep ring
Where is the deep inguinal ring?
midpoint of inguinal ligament
How would a hernia present?
non pulsatile, reducible, soft and non tender swelling
What is a strangulated hernia? How would it present?
comprimised blood supply - ischaemia
pain ++
irreducible and tender tense lump
What is an incarcerated hernia?
contents unable to return to original cavity
irreducible
How would an obstructed hernia present?
distension, vomiting, constipation
How can you tell the difference between an inguinal and a femoral hernia?
location
superomedial to pubic tubercle - inguinal
inferolateral to pubic tubercle - femoral
How are hernias diagnosed?
clinical diagnosis
USS if unclear diagnosis
What are the indications for surgery for hernias?
symptomatic
risk of complications (e.g. femoral hernias)
strangulation (urgent surgery)
What is the conservative management of hernias?
discuss symptoms of hernia emergencies (strangulation) and tell to go to A+E if they have them
What is the surgical management of hernias?
open or laparascopic mesh repair
What are the complications of hernia surgery?
chronic pain
recurrence
damage to structures e.g. vas deferens
What hernia has a high risk of strangulation?
femoral
due to narrow neck of canal
Who is more likely to get femoral hernias?
elderly women
What can cause a bowel obstruction?
intraluminal
- faecal impaction
- gallstone ileus
- foreign object
mural (wall)
- carcinoma
- inflammatory strictures
- diverticular strictures
- radiotherapy strictures
extramural
- hernias
- peritoneal mets
- adhesions
What causes a large bowel obstruction until proven otherwise?
cancer
What is a functional obstruction or paralytic ileus?
bowel not mechanically blocked but still not working
causes - inflammation, post surgery, electrolyte derangement
Why is urgent fluid resuscitation needed in bowel obstruction?
when bowel segment occluded
gross dilatation of proximal limb results in increased peristalsis
secretion of large volumes of electrolyte rich fluid
What is a closed loop obstruction?
when a second obstruction occurs proximally to first obstruction
What can cause a closed loop obstruction?
e. g. large bowel obstruction and competent ileocaecal valve
e. g. volvulus
What happens in a closed loop obstruction?
bowel continues to dilate and dilate, stretches wall until ischaemia or perforation
What are the clinical features of a bowel obstruction?
crampy abdo pain (secondary to increased peristalsis)
- should not have guarding or rebound tenderness
- unless ischaemia developing
vomiting
- if large bowel, ?no vomiting - due to ileocaecal valve
absolute constipation
- develops later on in proximal obstruction
distension
- tympanic percussion
When might you get bilious vomit in bowel obstruction?
if obstruction is distal to duodenal papilla
What are the investigations for suspected obstruction?
urgent bloods - electrolyte changes venous blood gas - ischaemia - increased lactate - metabolic derangement (vomiting, dehydration) CT scan with IV contrast - more sensitive than AXR - can show site and cause AXR
How can you tell if it is small bowel or large bowel obstruction on AXR?
- small bowel: central abdo, >3cm, valvulae conniventes visible
- large bowel: peripheral location, >6cm, haustral lines visible
What is the conservative management of bowel obstruction?
NBM
analgesia
IV fluids, catheter and fluid balance
NG tube - decompress bowel
What is the surgical management of bowel obstruction?
laparotomy (?bowel resection)
What are the indications for surgery in bowel obstruction?
failure to improve 48 hrs conservative
signs of ischaemia or closed loop obstruction
small bowel obstruction in abdo with no previous surgery
cause that needs correcting (tumour, hernia)
What would signs of ischaemia be in bowel obstruction?
pain worse with movement
focal tenderness
pyrexia
guarding, rebound tenderness
What is a volvulus?
twisting of a loop of intestine around its mesenteric attachment
leads to closed loop obstruction
Wherecan a volvulus occur?
sigmoid
caecum
Why do volvulus most often occur in the sigmoid colon?
long mesentry
What sign is seen on AXR in sigmoid volvulus?
coffee bean sign
What is a caecal volvulus?
colonic obstruction + competent ileocaecal valve
What is the management of a volvulus?
sigmoidoscope decompression and flatus tube
surgery if: ischaemia or performation, failed decompression, necrotic bowel
What are risk factors for volvulus?
male
neuropsychiatric conditions
previous abdo surgery
What is Meckel’s diverticulum?
congenital outpouching of terminal ileum - embryonic remnant
- gastric mucosa (secretes stomach acid)
How does Meckel’s diverticulum present?
acute abdo pain
usually children
usually asymptomatic
How is Meckel’s diverticulum diagnosed and treated?
radionucleide scan - absorbed differently by stomach cells in diverticulum
surgical excision
What is angiodysplasia of the colon?
formation of AVMs between previously healthy blood vessels in the bowel
What are the clinical features of angiodysplasia?
fresh, intermittent rectal bleeding
painless
anaemia
What is the management of angiodysplasia?
endoscopy coagulation
if more severe: embolisation or surgical resection
How does GI malabsorption present?
weight loss, malnutrition abdo bloating steatorrhoea diarrhoea flatulence
What are the causes of GI malabsorption?
infection - giardiasis
pancreatic insufficiency - CF, cancer
bowel causes - Crohn’s, coeliac, lactose intolerance, Whipples, tropical sprue
How would you investigate malabsorption?
bloods: FBC, B12, anti TTG, calcium, folate
stool sample (microscopy)
hydrogen breath test
OGD and biopsy
What is coeliac disease?
autoimmune hypersensitivity to gluten
T cell mediated response leading to villous atrophy
How is coeliac disease diagnosed?
serum anti-TTG
confirmed with OGD + duodenal biopsy (villous atrophy)
How is coeliac managed?
life long gluten free diet
How does coeliac disease present?
chronic, intermittent diarrhoea failure to thrive fatigue persistent GI symptoms anaemia weight loss
What is lactose intolerance?
deficiency of lactase enzyme, causing intolerance of lactose
symptoms on eating dairy
What causes lactose intolerance?
congenital - rare
usually secondary to infection, insult to bowel
What is Whipples disease?
rare bacterial infection caused by Tropheryma whipplei
causes multisystem disorder
middle aged men
How does Whipples disease present?
symptoms of malabsorption
arthritis
hyperpigmentation
How is Whipples diagnosed and managed?
OGD and biopsy
PAS +ve macrophages, saggy mucosa
long term antibiotics
How is bacterial overgrowth diagnosed?
hydrogen breath test
