gi middle tier Flashcards
which part of the bowel gets obstructed more (small/large)
small
where is volvulus obstruction v common
south africa
LIC
4 different causes of intestinal obstruction (vague)
- something in lumen
- something in gut wall - intramural
- something outside of gut
- pseudo obstruction
something in lumen - causes of obstruction
Tumour
Diaphragm disease
- narrowed lumen of small bowel
- Fibrous
- Associated with NSAIDs
Gallstone ileus
- Large gallstone in small bowel (couldn’t have fit (bile duct/sphincter of oddi) → erodes through to small bowel)
- rare
intramural - causes intestinal of obstruction
Inflammation
Ulcerative colitis
Crohn’s disease
- Can affect anywhere
- Fibrous, granulomas make up cobblestone mucosa
Diverticular disease
- Inflammation of pockets/ cul-de-sacs in the colon (usually sigmoidal colon). Can rupture → faecal peritonitis
- These form as mucosa goes through weak spots in muscularis due to high gut pressure (low fibre diet)
Tumours
Hirschprung’s disease
- Birth defect, usually neonatal presentation
- Rectum is aganglionic (cant contract due to lack of innervation) so proximal bowel fills with faeces (backlog) and dilates
- Functional mechanism (rather than mechanical)
- Abscence of contractions = adynamic, paralytic
Intussusception
- One hollow structure in another like a telescope
- Seen more in children as bowel is softer
whats is hirschprung’s disease
- Birth defect, usually neonatal presentation
- Rectum is aganglionic (cant contract due to lack of innervation) so proximal bowel fills with faeces (backlog) and dilates
- Functional mechanism (rather than mechanical)
- Abscence of contractions = adynamic, paralytic
something outside of gut causes of intestinal obstruction
Adhesions
- Between bowel bits, causing obstruction by pulling odd-ly. Prevent free movement
- Often post-op – surgeREHH
- Common
- Easily corrected - lysis
Volvulus
- Sigmoidal colon less attached- long mesentery. So it twists on itself to create a volvulus (mesentry required)
- 360 degrees = total obstruction
- LIC
- Closed loop obstruction (type)
Peritoneal tumour
- Peritoneal cancer eg ovarian cancer, spreads to peritoneum where it grows easily
- Hard to treat - can’t remove the peritoneum
Hernias
- Abnormal protrusion of organ/tissue through a cavity
- Strangulation (type)
causes of psuedo obstruction (intestinal)
Intra abdominal trauma/sepsis Fractures Pneumonia Drugs (opiates, antidepressants) Malnutrition Parkinson’s
which intestinal obstructions happen in small/large bowel
small
- Mainly adhesions (previous surgery)
- Hernias - especially LIC
- Malignancy
- Crohn’s
large
- volvulus
- less common than small bowel obstructions
effects of blockage small/large bowel
dilation proximal to blockage
small bowel
- increased secretions
- Swallowed air
- Decreased absorption
- Wall oedema
- Increased pressure → vessel compression → ischaemia, perforation
large bowel
- Wall oedema
- Increased pressure → vessel compression → ischaemia, perforation (esp caecum
- Electrolyte imbalance
- Bacterial translocation (through wall!) - lots of them – sepsis
presentation of intestinal obstruction
- Anorexia, nausea,
- vomiting (profuse)
—Faecal -like = more large than small bowel (more digested) - Pain
— More constant in large, than small bowel - Constipation (obstipation = more severe, complete)
- No farting (esp small bowel)
- stool blood
- Distension
— The more distal, the greater the distension - Bacteria overgrowth
- Tenderness suggests strangulation
- Increased bowel signs
fluid/electrolyte imbalance due to increased secretions - Palpable mass (hernia, tumour, distended loop/caecum)
psuedoobstruction presentation
Rapid abdominal distention
Rapid onset pain and getting worse
investigations into intestinal obstruction
Bloods
- Low hb - blood loss
- Rule out other causes ?
Abdominal X ray
- Gas shadows proximal to blockage
- Distended loops proximal to obstruction
- Fluid levels
CT
- Can locate well
Digital rectal exam PR
- Empty rectum, hard stool, blood
intestinal blockage management
inc what NOT to give
Nasogastric tube - ‘drip and suck’ - sucks out contents
IV fluids to rehydrate and correct electrolyte imbalance
Analgesia
Antiemetics
Antibiotics
Surgery
NO laxative – cause bowel to perforate
where does diverticulus mainly occur?
diverticulus age
sigmoidal colon mainly (or descending). can be anywhere in bowel (mainly large bowel)
over 50y. rare in young
diverticulitis causes
Low fibre diet - Colon needs to push harder to move things along (fibre helps gut motility) so pressure increases → pouches of mucosa extruded through muscular wall Obesity Smoking NSAIDs
diverticulum =
diverticulosis =
diverticular disease =
diverticulitis =
Diverticulum = outpouching of gut wall
- Usually at sites of entry of perforating arteries
- Wall is weaker here
Diverticulosis = presence of diverticula
Diverticular disease = diverticula are symptomatic (infection, haemorrhage)
Diverticulitis = inflammation of diverticulum
- Faeces obstruct neck of diverticulum → stagnation → bacteria proliferate → inflammation
meckel’s diverticulum=
- what
- where
- appears how
- treatment
= congenital
- Diverticulum from ILEUM, not colon
- Usually asympomatic
- Clinically indistinguishable from acute appendicitis if they inflame acutely
- Treatment = surgery
how to differentiate appendicits and diverticulitis
These symptoms/signs are similar to appendicitis BUT appendicitis is on RIGHT and diverticulitis is on the LEFT (usually)
signs of diverticulitis
- Fever
- Tachycardia
- Tenderness, guarding, rigidity on L abdomen
- Palpable mass in L iliac fossa sometimes
symptoms of diveticulitis
- Normally asymptomatic - detected incidentally on colonoscopy or barium enema examination
- Intermittent L iliac fossa pain
- Erratic bowel habit
- Constipation and pain due to luminal narrowing
diverticulitis investigations
CT Colonic wall
- = best, diagnostic
- Colonic wall thickening
- Diverticula
- Pericolic collections /abscesses
Bloods
- Leukocytes raised (polymorphonuclear leucocytosis == neutrophils ++)
- Raised ESR/CRP
AXR -
- May reveal obstruction
- May reveal free air –= indicative of perforation
Barium enema
Colonoscopy/sigmoidoscopy
- not for acute!!! Just diverticulosis may be picked up incidentally through this
diverticulitis management
High fibre diet Smooth muscle relaxants Antibiotics Fluids sometimes Surgical resection only required occasionally
diverticulitis complications
Perforation
→ abscesses
→ peritonitis
Surgery may be required
Fistula formation
- Into bladder
- – → dysuria (pain weeing)
- – Pneumaturia (gas in urine - bubbles)
- Into vagina
- – → discharge
Intestinal obstruction
- Usually after repeated episodes of acute diverticulitis
Bleeding
Mucosal inflammation
- May give appearance of crohns on endoscopy
