Ischaemic colitis and diverticulitis Flashcards
Outline the pathology of ischaemic colitis
Compromised perfusion to the marginal branches of the middle colic (SMA) and left colic (IMA) that supply the transverse and descending colon.
Which area of the colon is particularly susceptible to ischaemic colitis?
Splenic flexure
Name 3 predisposing factors for ischaemic colitis
Thrombosis of IMA AAA repair commonly ligates IMA Emboli Decreased CO or arrhythmias Shock Trauma Strangulated hernia or volvulus Drugs: OCP, cocaine, antihypertensives, psychotropic Abdominal surgery Vasculitis Coagulation disorders
Describe the presentation of ischaemic colitis
Sudden onset of abdominal pain, commonly in LIF
-typically occurs after eating
-pain out of proportion to clinical findings
Bright red PR bleeding
NaV
Diarrhoea
How should ischaemic colitis be investigated?
Urgent CT to exclude perforation
AXR would show thumb printing
Flexible sigmoidoscopy
Biopsy ➔ epithelial cell apoptosis and lamina propriety fibrosis
Later: Colonoscopy to exclude strictures and confirm mucosal healing
How is ischaemic colitis managed?
Many cases are resolved by correcting hypoperfusion
Symptomatic treatment
Surgery if fulminant ischaemic colitis + perforation/gangrene
Define diverticulum
Herniation of mucosa through thickened colonic muscle
Where are diverticula most commonly seen?
Sigmoid (85%) and descending colon
What lifestyle factor is diverticulum formation associated with?
Low-fibre diet - seen most in USA, Europe, and Australia
Name and describe the 3 conditions associated with diverticula
Diverticulosis (95%): Presence of asymptomatic diverticula
Diverticular disease: Symptomatic diverticula
Diverticulitis: Diverticular inflammation
What percentage of people aged 50+ have diverticula?
50%
Name 3 risk factors for diverticular disease
Aged 50+
Low fibre diet
Obesity
Complicated diverticular disease is commoner in patients who smoke, use NSAIDs, obese, low-fibre diets.
How does diverticulosis present?
Frequently an incidental finding on colonoscopy or barium enema.
How does diverticular disease present?
Large painless rectal bleed
Nonspecific abdominal complaints, usually left-sided:
-Intermittent lower abdominal/LIF pain
-Erratic bowel habit
Severe disease ➔ severe pain and constipation
Pain exacerbated by eating, diminished with defecation or flatus
NB. Isolated diverticular bleeds in absence of infection tend to spontaneously resolve ➔ active observation
How does diverticulitis present?
Severe lower abdominal pain Fever Malaise Change in bowel habit Rectal bleeding (occasional)
