Week 6 lower Gi tract Flashcards
What are the two types of diverticula?
Acquired –> develop during post natal life
Congenital
What is a diverticula?
Diverticula are blind ending outpouching of the bowel
What is diverticulosis of the colon?
Protrusions of mucosa and submucosa through the bowel wall. Commonly sigmoid colon but can extend into the proximal colon and cecum.
Where in the bowel wall do diverticulosis usually develop?
Located between mesenteric and anti-mesenteric taenia coli
What part of the world is diverticulosis more common in and what type of area ?
Common in developed ( western ) world
Rare in Africa , Asia , S. America
Common in urban cf. rural areas
Changing prevalence in migrant populations
What age group do you see diverticulosis mainly in and does diet have a affect?
Under the age of 40 it is rare but after 40 it becomes more and more common.
Male and females are equal.
However diet plays a part as there is a relationship between fibre content of diet.
Therefore less common in vengetarians due to less fibre
What are the 3 main types of diverticulosis?
Sigmoid diverticulosis
Diverticulosis of the right colon
Giant diverticulum
What is the pathogensis of diverticulum?
There is increased intra lumen pressure casued by Irregular , uncoordinated peristalsis which occurs in the sigmoid colon. Also overlapping semicircular arcs of bowel wall which caused increased pressure in the colon due to the irregular peristalsis.
Causing a point of relative weakness in the bowel wall–> caused by Penetration by nutrient arteries between mesenteric and antimesenteric taenia coli.
Can also be due to age related changes in the connective tissue
How does diverticulosis develop?
Thickening of muscularis propria ( earliest change – “prediverticular disease” )
Elastosis of taeniae coli ( leading to shortening of colon due to contraction of the taenia coli
Redundant mucosal folds and ridges due to the shortening
Sacculation and diverticula
What is the usual clinical features of diverticular disease?
Asymptomatic ( 90 – 99 % )
Cramping abdominal pain
Alternating constipation and diarrhoea
Not to many problem
What percentage of people get chronic or acut complications of diverticular disease?
10-30%
What are the acute complications of diverticulosis?
You get diverticulitis which leads to peridiverticular abscess.
Perforation due to infection of the peritoneal cavity.
Finally can get haemorrhage if the surrounding artery or veins are ulcerated.
What is diverticulitis?
It is inflammation in the diverticula due to ulceration of diverticula lining and invasion of bacteria into the surrounding tissue.
What are the chronic complications of diverticulosis?
Intestinal obstruction ( strictures : 5 – 10 % )
Fistula ( urinary bladder, vagina )
Polypoid prolapsing mucosal folds
Diverticular colitis ( segmental and granulomatous ) –> inflammation in the lining of the bowel –> diarrhoea and rectum bleeding
What is colitis?
Inflammation of the colon usually causing mucosal inflammation but occasionally transmural or predominantly submucosal/muscular
What type of colitis causes inflammation in the transmural?
Crohns disease
What type of colitis causes inflammation in the submucosal/mscular?
Eosinophilic colitis
What can colitis be divided into?
Into acute or chronic
What are the different examples of acute colitis?
Acute infective colitis Antibiotic associated colitis Drug induced colitis Acute ischaemic colitis ( transient or gangrenous ) Acute radiation colitis Neutropenic colitis Phlegmonous colitis
What are the different classification 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
What are the main 2 types of idiopathic inflammatory bowel diseaese?
ULCERATIVE COLITIS
CROHN’S DISEASE
INDETERMINATE COLITIS ( 10 – 15 % )
What is more common UC or CD?
UC is more common and the incidence is highest in Scandinavia, UK, Northern Europe, USA
What is the peak age incidence of both UC and CD?
Between the age of 20-40 years of age
Is CD or UC more common in males or females?
CD is more common in females
For UC it is equally common in males andd females
Is smoking a risk factor for both UC and CD
For crohns it is a risk factor but it seems to decrease chance of getting UC.
Other than smoking what other factor can potentially increae your risk of IBD?
Oral contraceptive
Is there any familial clustering in IBD?
Yes there is if you have a family member who has UC or CD then the chances of you have either increases dramatically.
What is the clinical presentation of UC?
Diarrhoe with urgency/tenesmus Constipation Rectal bleeding Abdominal plain Anorexia Weight loss Anemia due to the excessive loss from rectal bleeding
What are the complications of UC?
Toxic meacolon and perforation
Haemorhage
Stricture –> rare in UC–> if you see it in UC then sign of cancer
Carcinoma
How is toxic megacolon and perforation caused in UC? How do you treat it?
Toxic megacolon is caused by UC having a remitting and relaxing course - occasionally get a very severe flare up that badly damages the colon wall, particularly affecting the transverse colon,
Get a severely inflamed and dilated transverse colon, gas can build up, leading to perforation. 40% die when this happens.
Treated with high dose steroids –> If it does not work then need to have the bowel removed before perforation
where does UC typical begin and where does it spread?
Typically starts in the rectum and goes to variable part of the colon –> continous
What are the two histological findings for UC?
Crypt abscess and crypt distortion
What are the clinical features of crohns disease?
Chronic relapsing disease like Uc Affects all levels of GIT from mouth to anus Diarrhoea ( may be bloody ) Colicky abdominal pain Palpable abdominal mass Weight loss / failure to thrive Anorexia Fever Oral ulcers Peri – anal disease anaemia
What is the action of peri-anal disease caused by CD?
Ulcers, strictures, fistula of the anus into the skin/vagina
What parts of the GI tract affected by CD and UC and how does it spread?
CD is patchy and can affect the whole GI tube –> mouth to anus
UC –> affects colon, appendix and terminal ilium but is a continous diseae
What is the most common distruction of crohns disease?
Ileocolic distribution.
Affects the end of the small intestines and the start of the large intestines