GI Problems One: Luminal pathology Flashcards
If someone has diarrhoea for less than two weeks what is likely diagnosis?
Infection, improving within timeframe
If someone develops diarrhoea over months, what excludes infection as a differential?
- History is too long in an otherwise fit and well person.
- Immunocompromised can be longer: / Exclude C.difficile in someone with recent antibiotics.
What history questions do you ask for someone with diarrhoea?
- Consistency
- Frequency
- Appearance +/- blood
What rules out coeliac disease?
Unlikely with bleeding
(villi destruction -> malabsorption and diarrhoea, no inflammation therefore no bleeding)
What rules out irritable bowel syndrome?
- Unlikely when bowel habit is regular
- Bleeding unlikely
- Nocturnal diarrhoea - unlikely
Lower abdominal cramps suggests pain in which organ?
Hindgut - colon
Whats a common presentation of IBS?
Bleeding and diarrhoea
When is bowel cancer uncommon?
Not usually in a young person unless family history of polyp syndrome
Why do people with prolonged inflammation develop a normocytic anaemia?
Inflammation shuts down bone marrow and red cell production
How does occult bleeding change heamatocrit?
- Acute bleeding can drop Hb without change in MCV
- Chronic bleeding can drop Hb but usually MCV also falls due to iron deficiency
What does low albumin and high ferritin suggest?
Acute phase reaction
Whats the two common types of inflammatory bowel disease?
Crohns disease
Ulcerative collitis
What is crohns? Where does it occur? What makes it worse?
Describe its appearance.
- DISCONTINUOUS ‘skip lesions’ inflammation (TRANSMURAL; Ulcer-> penetrating ulcer with fissuring)
- Any part of GI
- Made worse by smoking.
Can appear as deep ulcers with cobblestone appearance. Granulomas may be present. Can be inflammatory, fistuling, stricturing, perianal.
Can infection cause bloody diarrhoea?
Yes many can.
What is ulcerative collitis? Where does it occur? What does it look like?
- Colon only
- Continuous inflammation from rectum
- Shallow ulceration of mucosa.
- Inflammatory
Smoking protects.
How does the inflammatory component of crohns present?
- Colitis = Diarrhoea, bleeding
- Ileitis = Abdo pain, ~1hr post prandial
- Gastritis/duodenitis = dyspepsia
What does stricturing in crohns result in?
- Abdo pain and distension
- Vomiting
- Bowels not opening
What sorts of fistulas occur in crohns?
Fistula = An abnormal connection / tract between the gut and another organ / vessel
- SI -> Skin
- SI -> SI
- Rectum and vagina
- Oesophagus and trachea
What perianal features can appear in crohns?
- perianal abscess
- Perianal fistula
- Anal fissure
Whats the clinical feature of ulcerative collitis?
- Diarrhoea, bleeding
- Frequent bowel motions and urgency
- Abdo discomfort
- Fever, malaise, weight loss
- Raised ESR/CRP, platelets
What are the phenotypes of crohns disease?
Fistulas
Structuring
Inflammatory
Perianal
What can happen in UC if inflammation extends to the smooth muscle?
Toxic megacolon - arrested smooth colonic movement leads to progressive dilatation
Whats the treatment of IBD in general?
- 5-ASA (mild antiinflam)
- Steroids
- Immunosuprresion
- Anti-tumour necrosis factor
What are the principles of surgery? when it comes to IBD?
When medical treatment fails
= Resect diseased bowel i.e colectomy. Ileal resection
Treatment of bowel complications
- Bowel obstruction
- Perforation
- Fistula
- Abscess
In crohns no cure
Where is B12 absorbed?
Terminal ilium therefore removal of the terminal ilium removes the specialised B12/IF receptors
What is the role of bile salt malabsorption in inflammatory bowel disease?
- Reduced re-uptake of bile salts via enterhepatic circulation
= Bile salts loss
= Fat malabsorption and fatty diarrhoea (steatorrhoea)
Bile salts in colon irritate colon, stimulate water and electrolyte secretion = secretory diarrhoea.
What is the likely source of rectal bleeding?
- Upper GI unlikely unless melaena.
- Lower GI tract: likely
- Outlet (heamorrhoids / fissure): fresh on paper, not likely to cause iron deficiency
Describe the colours of stool blood and likely source:
Black: Melaena: Upper GI/SI
Bright red on paper: Perinal
Bright red mixed with stools: Left colon
Dark red - Proximal colon, distal to SI
Whats the autoantibody in coeliacs?
- IgA tissue transglutaminase antibodies
What are some potential causes of erratic bowel habit?
- Ceoliac
- Irritable bowel syndrome
