Gastrointestinal Medicine - 2 Flashcards
What possible general causes of IBD?
- Food intolerance
- Persisting viral infection/immune activation
- Smoking
- Genetic
What is a possible microbiological cause of crohn’s?
infection with mycobacteria (paratuberculosis) after possibly drinking milk with cattle infected with johne’s diseases
UHT kills mycobacteria - pasteurisation does not
What can disease in the ileocecal region result in?
Vit b12 malabsorption
Where can crohn’s disease affect?
any part of the GI tract even oral
What are the ulcerative colitis sites?
starts at the distal part of the bowel (rectum) and moves forward throughout the lage intestine
Features of UC
Affects only the colon and rectum (continuous involvement)
Always involves the rectum
Lower rate of anal fissures (25%)
Mucosal inflammation only
Vascular pattern of inflammation
No granulomas
Does not cause obstructions or fistulas
No malabsorption unless severe disease
Serosa normal
Features of Crohns
Can affect any part of the GI tract (discontinuous involvement)
Often affects the terminal ileum (30%)
Rectum involved in only 50% of cases
High rate of anal fissures (75%)
Transmural inflammation (through all layers of bowel wall creating cobbled apperance)
Non-vascular pattern of inflammation
Granulomas present on biopsy
Can cause obstruction, fistulas, abscesses
Higher risk of malabsorption
Serosa inflammed
What is the appearance of the mucosa in crohns disease?
cobblestone appearance due to linear ulceration seperated by fibrous bands
narrowed lumen
thickened wall
What are the common symptoms of ulcerative colitis and crohns?
Abdominal pain
Diarrhea
Rectal bleeding
Extra-intestinal manifestations like arthritis
What are the investigations used to identify IBD?
- blood tests
- faecal calprotectiin
- endoscopy
- leukocyte scan
- barium radiography
- bullet endoscopy
What biomarker is increased in IBD
- faecal calprotectiin
What are the blood tests measuring?
anaemia
CRP - c reactive protein
ESR - erythrocyte sedimentation rate
What are complications of ulcerative colitis?
developing carcinoma over time
What are the drugs used to treat IBD?
what are examples of each
Steriods - Local or Systemic (immunosuppressive)
5-Aminosalicylic Acid (5-ASA) - Anti inflammatory drugs
Non Steroid immunosuppresants
Anti TNFα therapy
What surgery can cure UC?
colectomy
What pallative (not curable) surgeries can be used to treat crohn’s disease?
- Remove obstructed bowel segments
- Drain abscesses
- Close fistulae – especially perianal
What is the oral manifestion of crohns?
what features does it have and what can trigger it
orofacial granulomatosis
Granuloma formation blocks lymphatics leading to inflammtion/swelling of mouth/face, fissures, and cobbling
can be triggered by benzoate/sorbate/cinnamon (food preservatives and additives)
Why does bowel cancer usually mean colonic cancers?
tumours in the SI are unusual and most likely related to lymphma or hormonal conditions
What are the symptoms of colonic carcinoma?
why is there sometimes none?
patient may not have symptoms until the tumour completely blocks and the patient presents with obstruction
- anaemia and rectal blood loss due to bleeding from tumour
What is the cause of colonic carcinoma?
polyps
- Most carcinomas arise in polyps
- May be pedunculated or flat
- Most will bleed due to irritation and trauma
- Most take 5 years to progress to malignancy
What are the medical and familial causes of colonic carcinoma?
- Genetics – p53 in 75% (tumour suppresser gene mutation)
- Ulcerative Colitis
- Intestinal polyps
What are the patient controlled causes of colonic carcinoma?
diet high in fat and meat, low in fibre/veg
smoking
excess alcohol
lack of exercise
What conditions are polyps high risk for carcinoma?
in large intestine
- Gardiners Syndrome
- Cowden’s Syndrome
What conditions are polyps low risk for carcinoma?
in small intestine
peutz-jehgers symdrome
What is duke’s classes for colonic carcinoma staging?
A Submucosal
B Muscularis
C Lymph nodes
D Liver
What is treatment for colonic carcinoma?
- Surgery
- Hepatic Metastases - if disease has spread to liver then care is palliative
- Radiotherapy
- Chemotherapy
What surgeries can be used to treat colon cancer?
resection of the colon with anastomosis
section removed and stoma created for colostomy bag
What is used for colonic carcinoma screening?
FIT (faecal immunochemical test) from age 50, 2 year repeat - looks for blood in stool
Endoscopy if FIT positive
Other Screening modalities:
* Barium Enema
* Endoscopy
* CT/MRI Scan
* Carcinoembryonic Antigen (CEA)
