LOWER GI tract Flashcards
Name some parts of the Lower GI system…
- Appendix
- Colon (ascending, transverse, descending, Sigmund)
- Rectum
- Anus
What is appendicitis?
It’s an acute bacterial infection of the appendix precipitated by the obstruction of the lumen.
What are some clinical signs/symptoms of appendicitis?
- Pain
- Rebound tenderness
- Systemic symptoms
What problem is this describing:
Acute inflammation of the colon presenting with the formation of plaquelike fibrinous exudate (pseudomembranes) covering parts of the large intestinal mucosa. Caused by a toxin produced by C.Difficile which is replacing the normal intestinal flora.
PSEUDOMEMBRANOUS COLITIS
What’s pseudomembranous colitis?
It’s acute inflammation of the colon. With the formation of plaquelike fibrinous exudate (pseudomembranes) covering parts of the large intestinal mucosa. It’s caused by a toxin produced by an overgrowth of C.Difficile replacing the normal intestinal flora.
What are pseudomembranes?
They’re plaque like fibrinous exudate which covers the large intestine in pseudomembranous colitis
What bacteria causes pseudomembtanous colitis?
C. Diff
Who is at risk of pseudomembranous colitis?
Patients who have been treated with broad spectrum antbix because it provides a nice environment for C.Diff
Treatment for Pseudomembranous colitis.
- Discontinuation of antibiotics (that may have caused it in first place)
- Hydration
- Specific antibacterial therapy
Mrs X has fever and lower abdominal tenderness, she has just been treated with broad spectrum antibiotics, what could be wrong with her?
PSEUDOMEMBRANOUS COLITIS
Crohn’s disease and Ulcerative colitis are two types of what disease?
Inflammatory Bowel Disease
What’s Inflammatory Bowel Disease
It’s chronic inflammatory conditions of unknown aetiology affecting the GI tract. (Crohn’s and ulcerative colitis)
True or false?
Crohn’s disease only affects the colon.
FALSE
Crohn’s can affect any part of the GIT from mouth to anus!
What are some pathological features of IBD Crohn’s disease.
- Mucosal ulceration typically fissuring
- Oedema of adjacent epithelium (cobblestone)
- Pseudopolyp formation regeneration
What disease are these pathological features of:
- Mucosal ulceration typically fissuring
- Oedema of adjacent epithelium (cobblestone)
- Pseudopolyp formation regeneration
Crohn’s Disease (Inflammatory Bowel Disease)
Which lower GI disease can cause fistula formation?
Crohn’s disease can cause fistula formation:
- Bowel to bowel
- Bowel to vagina
- Bowel to bladder
- Bowel to skin
What are some of the complications of Crohn’s Disease?
- Anemia
- Malabsorbsion of fat, vit a.b.e.k from iron deficiency
- Fistulas
- Extra Intestinal: skin, eyes, joints
- Slight increased risk of bowel cancer
True or false
Ulcerative colitis can have an affect anywhere from mouth to anus?
FALSE
It’s a disease of the colon only and starts in rectum and spreads proximally. Only a disease of the mucosa (unlike crohn’s)
Which Inflammatory Bowel disease has transmural involvement (all layers of the colon)
Crohn’s Disease
Ulcerative colitis is a disease of the mucosa only
What inflammatory bowel disease causes crypt abscess formation and pseudopolyp formation?
Ulcerative Colitis
What are some of the complications associated with Ulcerative colitis?
- Anaemia: Iron deficiency from blood loss
- Elecrolyte loss from diarrhoea
- Extra-intestinal disease: skin, eyes, joints, bile ducts (psc)
- Increased risk of carcinoma (depends on disease severity)
- Need to monitor for dysplasia (abnormal growth)
There are some diseases that can mimic IBD (crohn’s and ulcerative colitis) what are some?
What are the mimics of IBD?
- Ischaemic colitis
- Radiation colitis
- Behcet’s disease
- Pouchitis
- Diversion colitis
- Microscopic (lymphocytic/collagenous) colitis
- Infectious colitis
- Iatrogenic colitis
What factors can predispose someone to getting Colorectal carcinoma?
- Genetic Factors (Family adenomatous polypis, lynch syndrome)
- Chronic Inflammation (IBD- UC, Crohn’s)
- Bad diet (low fibre, bile aerobes, red meat, lack of vits and antioxidents)
What is the NBCSP?
It stands for the national bowel cancer screening programmme.
All peop’ 60-75 yo are screened. Consists of Faecal occult blood test and if positive they have a colonoscopy and look for polyps (adenomas) and carcinomas)
What’s a lower Gastro-intestinal Adenoma?
It’s a benign tumour of glandular epithelium
Whats a lower GI polyp?
It’s a projection above an epithelial surface. Can be benign. They can be composed of epithelium, stroma, mixture (hamartoma), inflammatory tissue and lymphoid tissue)
True or false?
It’s very rare that malignant carcinomas of the lower GI tract can arise from benign adenomas (polyps)?
FALSE
Almost all carcinomas arise from benign adenomas (polyps). The more polyps, the greater risk. The larger the polyp, the more likely it is to be malignant.
What does FAP stand for in terms of lower gastrointetinal disease?
It stands for Familial Adenomatous Polyposis.
It’s where polyps develop mid teens and onwards. Carcinoma is inevetable (usually 15 years later). Need for genetic councelling.
What are Gardeners and Turcot syndromes variants of?
Gardeners and Turcot syndrome are variants of the lower GI disease of Familial Adenomatous Polyposis (FAP).
What genetically inherited lower GI disease (chromosome 5 APC gene 5a21) causes inevitable carcinoma ~15 years later?
Familial Adenomatous Polyposis
What genes/Chromosomes are associated with FAP (Familial Adenopmatous Polyposis)?
- Chromosomes 5
- APC gene 5q21
What’s another name for ‘Hereditary Non-Polyposis Colorectal Carcinoma’ (HNPCC)
Lynch Syndrome
What’s Lynch Syndrome?
It’s an hereditary disease, also known as Non-Polyposis Colorectal carcinoma (HNPCC). It is associated with cororectal cancer (70-85%) but also other cancers such as endometrial, small bowel, renal and ureter)
What is ‘Dukes’ in terms of Lower GI diseas?
It’s used for staging Colorectal Carcinoma.:
- Dukes stage A (above muscle layer, 5yr survival 95%)
- Dukes stage B (into serosal fat, LN negative, 66% 5yr survival)
- Dukes stage C (LN involvement, 33% 5 yr survival).
What Stage of the Dukes staging sytem for colorectal cancer encompases Lymph Node involvement?
DUKES STAGE C! (35% 5 year survival)
A- above mucle layer
B- Serosal fat layer
What’s the TNM tumour grading system for Colorectal Carcinoma?
T (Tumour size) , N (nodes?), M (metastesis)
What does ‘Tx’ Mean in the TNM grading system for Colorectal Carcinoma?
It means the primary tumour is not assesable.
What does ‘T0’ mean in the TNM grading system for Colorectal carcinoma>
It means no primary tumour
What does ‘T1. T2. T3. T4’ mean in the TNM grading system for colorectal cancer?
It means to tumour has spread to: T1- submucosa T2- Muscularis propria T3- Subseosa, perirectal tissues T4- Perforates visceral peritoneum (a) or invades other organs (b)
What does ‘N0’ mean in the TNM grading system for colorectal cancer?
It means no Lymph node metastasis.
What does ‘N1 and N2’ mean in the TNM grading system for colorectal cancer?
It mean the tumour has spread to lymph nods:
N1- 1-3 lymph node spread
N2- More than 4 LN spread
What certain features can affect the prognosis of colorectal carcinoma?
- Features of the primary tumour (TNM-dukes, invasion, ext)
- Surgical factors
- Evidence of vessel invasion (venous, lymmphatic envolvement)
- Evidence of host response (local inflam response, angiogenesis)
