Flashcards in Bowel pathology Deck (28):
Which part of the colon is affected most by cancer?
Rectum and sigmoid colon
How do colorectal cancers arise?
Adenomatous polyp forms and eventually becomes an adenocarcinoma.
As the polyp becomes larger it accumulates more gene mutations leading to unregulated cell growth, invasive potential and cancer development
What is dysplasia?
A microscopic diagnosis synonymous with intraepithelial neoplasia.
It is a combination of:
1) cytological atypia
2) architectural disorder
What are the two morphological types of Adenoma in the colon?
Name 2 familial polyposis syndromes
Familial adenomatous polyposis (FAP)
Hereditary non polyposis colon cancer (HNPCC)
What % of people with FAP develop adenocarcinoma before age of 45?
Which gene is mutated in FAP?
How do we screen for colorectal cancer?
FOB- faecal occult blood
What blood tests should be done to investigate malabsorption?
Fe, folate, B12
Breath tests- e.g. For bacterial overgrowth measure 14CO2 in breath
How can we test small intestine function?
Xylose absorption test
Xylose is absorbed in the jejunum and excreted unchanged in the urine.
This test is limited by renal function.
What are the 2 subtypes of IBD?
Which inflammatory bowel disease is granulomatous in nature?
What are the main differences between Crohn's disease and UC?
Mouth to anus
Thickened bowel wall
Deep fissuring ulcers
Normal bowel wall thickness
No fistula formation
What are the possible complications of diverticula disease?
Diverticulitis- leading to perforation and abscess formation
Intestinal obstruction due to inflammatory mass
Which two viruses are the commonest causes of childhood viral enterocolitis?
These can kill!
Which organism is responsible for pseudomembranous colitis?
Clostridium difficile (antibiotic-associated colitis)
What is hirschprungs disease?
Congenital aganglionosis- area of the bowel with no ganglion cells so it immotile. Need to resect as it causes constipation and can lead to megacolon.
What is intusussception?
A medical condition in which a part of the intestine invaginates into another section of intestine, similar to the way the parts of a collapsible telescope slide into one another.
What are the systemic causes of constipation?
Neurological (Parkinsonism, autonomic neuropathy)
What is the most common cause of diarrhoea?
What are the systemic causes of diarrhoea?
What bacterium might you get from reheated rice, causing diarrhoea?
What are the symptoms of irritable bowel syndrome?
Change in bowel habit
PR blood loss
Anaemia (suggests cancer)
Raised inflammatory markers
What can cause small bowel obstruction in Crohn's?
Stricturing or inflammation of a section of bowel
Patients who have had a bowel resection as a result of their inflammatory bowel disease can also get adhesions causing obstruction.
What can cause small bowel obstruction in UC?
Caecal inflammation, causing SBO at the ileocaecal valve
Where are the three locations for haemorrhoids?
Internal, interoexternal and external
How would you treat interoexternal haemorrhoids that get trapped externally and thrombose?
Painkillers and ice packs for symptomatic treatment.
Phenol 5% injection to cause ulceration and decrease vasculature.
Alternative: Barron's band to pull mucosa up.