GI Disease Flashcards
What are the 2 classifications of diverticula?
True “congenital” diverticulum or acquired “false” “pseudo” diverticulum
What are the 3 main types of diverticula seen in clinical practice?
Sigmoid diverticulosis ( acquired diverticula )
Diverticulosis of the right colon ( acquired and congenital diverticula )
Giant diverticulum
What is diverticulosis of the colon?
Protrusions of mucosa and submucosa through the bowel wall
Commonly sigmoid colon
Located between mesenteric and anti-mesenteric taenia coli ( also between anti-mesenteric t.coli in 50 % cases )
Less commonly extend into proximal colon
eg. Caecum ( 15 % )
What is the epidemiology behind diverticula?
Common in developed (western) world
Rare in Africa , Asia , S. America
Common in urban cf. rural areas
Changing prevalence in migrant populations
Relationship with fibre content of diet
Male = Female
Less common in vegetarians
Prevalence increases with age
What is the pathogenesis of diverticula?
Increased intra-luminal pressure
- Irregular , uncoordinated peristalsis
- Overlapping ( valve like ) semicircular arcs of bowel wall
Points of relative weakness in the bowel wall
- Penetration by nutrient arteries between mesenteric and antimesenteric taenia coli
- Age related changes in connective tissue
What is the pathology of diverticulosis?
Thickening of muscular propria-(earliest change – “prediverticular disease”)
Elastosis of taeniae coli (leading to shortening of colon)
Redundant mucosal folds and ridges
Sacculation and diverticula
What are the clinical features of diverticular disease?
Asymptomatic ( 90 – 99 % )
Cramping abdominal pain
Alternating constipation and diarrhoea
Acute and chronic complications ( 10 – 30 % )
What are the acute complications of diverticular disease?
Diverticulitis / peridiverticular abscess ( 20 – 25 % )
Perforation
Haemorrhage ( 5 % )
What are the chronic complications of diverticular disease?
Intestinal obstruction (strictures : 5 – 10%)
Fistula (urinary bladder, vagina)
Diverticular colitis (segmental and granulomatous)
Polypoid prolapsing mucosal folds
What is colitis?
“inflammation of the colon”
usually mucosal inflammation but occasionally transmural ( eg. crohns disease ) or predominantly submucosal/muscular ( eg. eosinophilic colitis )
divided into acute (days to a few weeks) and chronic (months to years)
What are the different types of acute colitis?
Acute infective colitis eg. campylobacter, salmonella, CMV
Antibiotic associated colitis ( including PMC )
Drug induced colitis
Acute ischaemic colitis ( transient or gangrenous )
Acute radiation colitis
Neutropenic colitis
Phlegmonous colitis
What are the different types of chronic colitis?
Chronic idiopathic inflammatory bowel disease
Microscopic colitis (collagenous & lymphocytic)
Ischaemic colitis
Diverticular colitis
Chronic infective colitis eg. amoebic colitis & TB
Diversion colitis
Eosinophilic colitis
Chronic radiation colitis
