Gastroenterology Flashcards
What conditions does alcoholic liver disease cover?
Alcoholic liver disease covers a spectrum of conditions:
alcoholic fatty liver disease alcoholic hepatitis cirrhosis
What are selected investigations for alcoholic liver disease?
Selected investigation findings:
gamma-GT is characteristically elevated the ratio of AST:ALT is normally > 2, a ratio of > 3 is strongly suggestive of acute alcoholic hepatitis
What medication can be used during acute episodes of alcoholic hepatitis? what is used to determine who would benefit from glucocorticoid therapy? what study compared the two common treatments?
Selected management notes for alcoholic hepatitis:
glucocorticoids (e.g. prednisolone) are often used during acute episodes of alcoholic hepatitis
Maddrey's discriminant function (DF) is often used during acute episodes to determine who would benefit from glucocorticoid therapy
it is calculated by a formula using prothrombin time and bilirubin concentration
pentoxyphylline is also sometimes used
the STOPAH study (see reference) compared the two common treatments for alcoholic hepatitis, pentoxyphylline and prednisolone. It showed that prednisolone improved survival at 28 days and that pentoxyphylline did not improve outcomes
Which 3 screening tools can be used for alcoholism?
CAGE
AUDIT
FAST
CAGE screening tool:
-What are the questions?
-what would be thought of as a ‘positive’ result?
well known but recent research has questioned it’s value as a screening test
two or more positive answers is generally considered a ‘positive’ result
C Have you ever felt you should Cut down on your drinking?
A Have people Annoyed you by criticising your drinking?
G Have you ever felt bad or Guilty about your drinking?
E Have you ever had a drink in the morning to get rid of a hangover (Eye opener)?
AUDIT screening tool:
-HOw many items in the questionnaire?
-What is the minimum and maximum score?
-What would indicate a strong likeligood of hazardous or harmful alcohol consumption?
-What would indicate alcohol dependance?
AUDIT
10 item questionnaire, please see the link takes about 2-3 minutes to complete has been shown to be superior to CAGE and biochemical markers for predicting alcohol problems minimum score = 0, maximum score = 40 a score of 8 or more in men, and 7 or more in women, indicates a strong likelihood of hazardous or harmful alcohol consumption a score of 15 or more in men, and 13 or more in women, is likely to indicate alcohol dependence AUDIT-C is an abbreviated form consisting of 3 questions
FAST questionnaire
-How many items?
-What is the minimum / maximum score?
-What would indicate hazardous drinking?
FAST
4 item questionnaire minimum score = 0, maximum score = 16 the score for hazardous drinking is 3 or more with relation to the first question 1 drink = 1/2 pint of beer or 1 glass of wine or 1 single spirits if the answer to the first question is 'never' then the patient is not misusing alcohol if the response to the first question is 'Weekly' or 'Daily or almost daily' then the patient is a hazardous, harmful or dependent drinker. Over 50% of people will be classified using just this one question
What are the questions in FAST questionnaire?
1 MEN: How often do you have EIGHT or more drinks on one occasion?
WOMEN: How often do you have SIX or more drinks on one occasion?
2 How often during the last year have you been unable to remember what happened the night before because you
had been drinking?
3 How often during the last year have you failed to do what was normally expected of you because of drinking?
4 In the last year has a relative or friend, or a doctor or other health worker been concerned about your drinking or
suggested you cut down?
What is the ICD definition of problem drinking?
ICD-10 definition - 3 or more needed
compulsion to drink difficulties controlling alcohol consumption physiological withdrawal tolerance to alcohol neglect of alternative activities to drinking persistent use of alcohol despite evidence of harm
Describe the government guidelines on drinking
The government now recommend the following:
men and women should drink no more than 14 units of alcohol per week they advise 'if you do drink as much as 14 units per week, it is best to spread this evenly over 3 days or more' pregnant women should not drink. The wording of the official advice is 'If you are pregnant or planning a pregnancy, the safest approach is not to drink alcohol at all, to keep risks to your baby to a minimum. Drinking in pregnancy can lead to long-term harm to the baby, with the more you drink the greater the risk.'
How much is one unit of alcohol equal to? and how is an alcoholic drink strength determined?
One unit of alcohol is equal to 10 mL of pure ethanol. The ‘strength’ of an alcoholic drink is determined by the ‘alcohol by volume’ (ABV).
Examples of one unit of alcohol:
25ml single measure of spirits (ABV 40%) a third of a pint of beer (ABV 5 to 6%) half a 175ml 'standard' glass of red wine (ABV 12%)
What is coeliac disease?
what kind of conditions is this associated with?
which markers is this associated with?
Coeliac disease is an autoimmune condition caused by sensitivity to the protein gluten. It is thought to affect around 1% of the UK population. Repeated exposure leads to villous atrophy which in turn causes malabsorption. Conditions associated with coeliac disease include dermatitis herpetiformis (a vesicular, pruritic skin eruption) and autoimmune disorders (type 1 diabetes mellitus and autoimmune hepatitis). It is strongly associated with HLA-DQ2 (95% of patients) and HLA-DQ8 (80%)
what 7 signs and symptoms exist for coeliac disease?
Chronic or intermittent diarrhoea
Failure to thrive or faltering growth (in children)
Persistent or unexplained gastrointestinal symptoms including nausea and vomiting
Prolonged fatigue (‘tired all the time’)
Recurrent abdominal pain, cramping or distension
Sudden or unexpected weight loss
Unexplained iron-deficiency anaemia, or other unspecified anaemia
Which conditions indicate that the patient should undergo coeliac disease screening? 5
Autoimmune thyroid disease
Dermatitis herpetiformis
Irritable bowel syndrome
Type 1 diabetes
First-degree relatives (parents, siblings or children) with coeliac disease
what 7 complications exist for coeliac disease?
Complications
anaemia: iron, folate and vitamin B12 deficiency (folate deficiency is more common than vitamin B12 deficiency in coeliac disease) hyposplenism osteoporosis, osteomalacia lactose intolerance enteropathy-associated T-cell lymphoma of small intestine subfertility, unfavourable pregnancy outcomes rare: oesophageal cancer, other malignancies
What investigations make up diagnosis for coeliac disease?
Diagnosis is made by a combination of serology and endoscopic intestinal biopsy. Villous atrophy and immunology normally reverses on a gluten-free diet.
NICE issued guidelines on the investigation of coeliac disease in 2009. If patients are already taking a gluten-free diet they should be asked, if possible, to reintroduce gluten for at least 6 weeks prior to testing.
What tests for serology is used for coeliac disease?
Serology
tissue transglutaminase (TTG) antibodies (IgA) are first-choice according to NICE
endomyseal antibody (IgA)
-needed to look for selective IgA deficiency, which would give a false negative coeliac result
anti-gliadin antibody (IgA or IgG) tests are not recommended by NICE
anti-casein antibodies are also found in some patients
What is the gold standard test for diagnosis coeliac? where is this done? what findings would suggest coeliac disease?
Endoscopic intestinal biopsy
the 'gold standard' for diagnosis - this should be performed in all patients with suspected coeliac disease to confirm or exclude the diagnosis
traditionally done in the duodenum but jejunal biopsies are also sometimes performed
findings supportive of coeliac disease:
villous atrophy
crypt hyperplasia
increase in intraepithelial lymphocytes
lamina propria infiltration with lymphocytes
Rectal gluten challenge has been described but is not widely used
What is the management of coeliac disease?
The management of coeliac disease involves a gluten-free diet. Gluten-containing cereals include:
wheat: bread, pasta, pastry
barley: beer
whisky is made using malted barley. Proteins such as gluten are however removed during the distillation process making it safe to drink for patients with coeliac disease
rye
oats
some patients with coeliac disease appear able to tolerate oats
Some notable foods which are gluten-free include:
rice potatoes corn (maize)
Describe the definitions of diarrhoea / acute diarrhoea / chronic diarrhoea
World Health Organisation definitions
Diarrhoea: > 3 loose or watery stool per day
Acute diarrhoea < 14 days
Chronic diarrhoea > 14 days
What are 4 clinical features of UGIB?
Clinical features
haematemesis
the most common presenting feature
often bright red but may sometimes be described as ‘coffee gound’
melena
the passage of altered blood per rectum
typically black and ‘tarry’
a raised urea may be seen due to the ‘protein meal’ of the blood
features associated with a particular diagnosis e,g,
oesophageal varices: stigmata of chronic liver disease
peptic ulcer disease: abdominal pain
what is a Dieulafoy lesion?
Often no prodromal features prior to haematemesis and melena, but this arteriovenous malformation may produce quite a considerable haemorrhage and may be difficult to detect endoscopically
What scores are used for UGIB?
Risk assessment
the Glasgow-Blatchford score at first assessment
helps clinicians decide whether patient patients can be managed as outpatients or not
the Rockall score is used after endoscopy
provides a percentage risk of rebleeding and mortality
includes age, features of shock, co-morbidities, aetiology of bleeding and endoscopic stigmata of recent haemorrhage
what urea levels give what score in blatchford scoring?
6·5 - 8 = 2
8 - 10 = 3
10 - 25 = 4
> 25 = 6
What Hb gives what score in blatchford scoring?
Men
12 - 13 = 1
10 - 12 = 3
< 10 = 6
Women
10 - 12 = 1
< 10 = 6
What systolic BP gives what score in blatchford scoring?
100 - 109 = 1
90 - 99 = 2
< 90 = 3
What other markers (not urea/Hb/BP) gives a score for blatchford scoring?
Pulse >=100/min = 1
Presentation with melaena = 1
Presentation with syncope = 2
Hepatic disease = 2
Cardiac failure = 2
Describe resuscitation of UGIB
-When is FFP used?
-when is prothrombin concentrates used?
Resuscitation
ABC, wide-bore intravenous access * 2
platelet transfusion if actively bleeding platelet count of less than 50 x 10*9/litre
fresh frozen plasma to patients who have either a fibrinogen level of less than 1 g/litre, or a prothrombin time (international normalised ratio) or activated partial thromboplastin time greater than 1.5 times normal
prothrombin complex concentrate to patients who are taking warfarin and actively bleeding
When should endoscopy be offered in UGIB?
Endoscopy
should be offered immediately after resuscitation in patients with a severe bleed
all patients should have endoscopy within 24 hours
Describe management of non-variceal bleeding?
Management of non-variceal bleeding
NICE do not recommend the use of proton pump inhibitors (PPIs) before endoscopy to patients with suspected non-variceal upper gastrointestinal bleeding although PPIs should be given to patients with non-variceal upper gastrointestinal bleeding and stigmata of recent haemorrhage shown at endoscopy
if further bleeding then options include repeat endoscopy, interventional radiology and surgery
Describe the management of variceal bleeding
Management of variceal bleeding
terlipressin and prophylactic antibiotics should be given to patients at presentation (i.e. before endoscopy)
band ligation should be used for oesophageal varices and injections of N-butyl-2-cyanoacrylate for patients with gastric varices
transjugular intrahepatic portosystemic shunts (TIPS) should be offered if bleeding from varices is not controlled with the above measures
Describe the involvement of the GI tract in crohn’s disease
whilst it may cause inflammation anywhere in the gastrointestinal tract, the disease burden is not evenly distributed:
80% of patients have small bowel involvement, usually in the ileum, with around 30% of patients having ileitis exclusively
50% of patients have ileocolitis
20% of patients have colitis exclusively
30% of patients have perianal disease
Describe the presentation of crohn’s disease
Crohn’s disease typically presents in late adolescence or early adulthood. Features include:
-presentation may be non-specific symptoms such as weight loss and lethargy
-diarrhoea
the most prominent symptom in adults
Crohn’s colitis may cause bloody diarrhoea
-abdominal pain: the most prominent symptom in children
-perianal disease: e.g. Skin tags or ulcers
extra-intestinal features are more common in patients with colitis or perianal disease
What blood tests would indicate crohn’s disease?
Investigations
raised inflammatory markers
increased faecal calprotectin
anaemia
low vitamin B12 and vitamin D
Describe extra intestinal features of crohns and colitis that are related to disease activity?
Arthritis: pauciarticular, asymmetric
Erythema nodosum
Episcleritis
Osteoporosis
Arthritis is the most common extra-intestinal feature in both CD and UC
Episcleritis is more common in CD
what are extra intestinal features of both crohns and colitis that are not related to disease activity?
Arthritis: polyarticular, symmetric
Uveitis
Pyoderma gangrenosum
Clubbing
Primary sclerosing cholangitis
Primary sclerosing cholangitis is much more common in UC
Uveitis is more common in UC
what lifestyle changes are advised for patients with crohn’s disease? does the contraceptive pill affect the disease?
General points
patients should be strongly advised to stop smoking
some studies suggest an increased risk of relapse secondary to NSAIDs and the combined oral contraceptive pill but the evidence is patchy
describe 6 methods of inducing remission in crohns disease?
Inducing remission
-glucocorticoids (oral, topical or intravenous) are generally used to induce remission. Budesonide is an alternative in a subgroup of patients
-enteral feeding with an elemental diet may be used in addition to or instead of other measures to induce remission, particularly if there is concern regarding the side-effects of steroids (for example in young children)
-5-ASA drugs (e.g. mesalazine) are used second-line to glucocorticoids but are not as effective
-azathioprine or mercaptopurine* may be used as an add-on medication to induce remission but is not used as monotherapy. -Methotrexate is an alternative to azathioprine
-infliximab is useful in refractory disease and fistulating Crohn’s. Patients typically continue on azathioprine or methotrexate
-metronidazole is often used for isolated peri-anal disease
what is used to maintain remission in crohns diseasE?
Maintaining remission
as above, stopping smoking is a priority (remember: smoking makes Crohn’s worse, but may help ulcerative colitis)
azathioprine or mercaptopurine is used first-line to maintain remission
What activity is checked before started azathioprine / metacapturine
+TPMT activity should be assessed before starting
methotrexate is used second-line
peri-anal fistulae
-What is this?
-what is the image modality of choice?
-what medical management can be used?
-what can be inserted in complex fistulae?
perianal fistulae
-an inflammatory tract or connection between the anal canal and the perianal skin
-MRI is the investigation of choice for suspected perianal fistulae - can be used to determine if there (is an abscess and if the fistula is simple (low fistula) or complex (high fistula that passes through or above muscle layers)
-patients with symptomatic perianal fistulae are usually given oral metronidazole
anti-TNF agents such as infliximab may also be effective in closing and maintaining closure of perianal fistulas
-a draining seton is used for complex fistulae
a seton is a piece of surgical thread that’s left in the fistula for several weeks to keep it open. This is useful because persisting fistula tracks after premature skin closure predispose to abscess formation
Describe the management of perianal abscess?
perianal abscess
requires incision and drainage combined with antibiotic therapy
a draining seton may also be placed if a tract is identified
Name 3 complication of crohn’s disease?
patients are also at risk of:
small bowel cancer (standard incidence ratio = 40)
colorectal cancer (standard incidence ratio = 2, i.e. less than the risk associated with ulcerative colitis)
osteoporosis
where does inflammation start and end in ulcerative colitis? what is the peak incidence?
Ulcerative colitis (UC) is a form of inflammatory bowel disease. Inflammation always starts at rectum (hence it is the most common site for UC), never spreads beyond ileocaecal valve and is continuous. The peak incidence of ulcerative colitis is in people aged 15-25 years and in those aged 55-65 years.
what is the nature of the initial presentation of UC? give 5 features
The initial presentation is usually following insidious and intermittent symptoms.
Features include:
-bloody diarrhoea
-urgency
-tenesmus
-abdominal pain, particularly in the left lower quadrant
-extra-intestinal features
what investigations are done for UC?
Endoscopy
barium enema
what kind of endoscopy is used for UC diagnosis?
colonoscopy + biopsy is generally done for diagnosis
however in patients with severe colitis colonoscopy should be avoided due to the risk of perforation - a flexible sigmoidoscopy is preferred
give 7 typical findings of endoscopy in UC?
typical findings:
-red, raw mucosa, bleeds easily
-no inflammation beyond submucosa (unless fulminant disease)
-widespread ulceration with preservation of adjacent mucosa which has the appearance of polyps (‘pseudopolyps’)
-inflammatory cell infiltrate in lamina propria
-neutrophils migrate through the walls of glands to form crypt abscesses
-depletion of goblet cells and mucin from gland epithelium
-granulomas are infrequent
What is seen on barium enema in UC?
Barium enema
loss of haustrations
superficial ulceration, ‘pseudopolyps’
long standing disease: colon is narrow and short -‘drainpipe colon’
What 5 factors can lead to UC flare?
Most ulcerative colitis flares occur without an identifiable trigger. However, a number of factors are often linked:
stress
medications
NSAIDs
antibiotics
cessation of smoking
How are flares of UC classified?
Mild / Mod / Severe
Describe a mild UC flare
Fewer than four stools daily, with or without blood
No systemic disturbance
Normal erythrocyte sedimentation rate and C-reactive protein values
Describe a moderate UC flare
Four to six stools a day, with minimal systemic disturbance
Describe a severe UC flare
More than six stools a day, containing blood
Evidence of systemic disturbance, e.g.
fever
tachycardia
abdominal tenderness, distension or reduced bowel sounds
anaemia
hypoalbuminaemia
Describe the treatment that is used to induce remission in proctatis with UC?
proctitis
topical (rectal) aminosalicylate: for distal colitis rectal mesalazine has been shown to be superior to rectal steroids and oral aminosalicylates
if remission is not achieved within 4 weeks, add an oral aminosalicylate
if remission still not achieved add topical or oral corticosteroid
Describe the treatment that is used to induce remision in proctosigmoiditis and left sided UC?
proctosigmoiditis and left-sided ulcerative colitis
topical (rectal) aminosalicylate
if remission is not achieved within 4 weeks, add a high-dose oral aminosalicylate OR switch to a high-dose oral aminosalicylate and a topical corticosteroid
if remission still not achieved stop topical treatments and offer an oral aminosalicylate and an oral corticosteroid
Describe the treatment of extensive disease in UC?
extensive disease
topical (rectal) aminosalicylate and a high-dose oral aminosalicylate:
if remission is not achieved within 4 weeks, stop topical treatments and offer a high-dose oral aminosalicylate and an oral corticosteroid
Describe the treatment of severe colitis
Severe colitis
should be treated in hospital
intravenous steroids are usually given first-line
intravenous ciclosporin may be used if steroid are contraindicated
if after 72 hours there has been no improvement, consider adding intravenous ciclosporin to intravenous corticosteroids or consider surgery
Ulcerative colitis - Describe the treatment used to maintain remission in:
-proctitis and proctosigmoiditis
-Left sided and extensiver ulcerative colitis
proctitis and proctosigmoiditis
-topical (rectal) aminosalicylate alone (daily or intermittent) or
-an oral aminosalicylate plus a topical (rectal) aminosalicylate (daily or intermittent) or
-an oral aminosalicylate by itself: this may not be effective as the other two options
left-sided and extensive ulcerative colitis
-low maintenance dose of an oral aminosalicylate
What treatment is used to maintain remission following a severe relapse or =>2 exac. in the past year of UC?
Following a severe relapse or >=2 exacerbations in the past year
oral azathioprine or oral mercaptopurine
How does 5-ASA treatment work?
5-aminosalicyclic acid (5-ASA) is released in the colon and is not absorbed. It acts locally as an anti-inflammatory. The mechanism of action is not fully understood but 5-ASA may inhibit prostaglandin synthesis
Sulphasalazine:
-what is this?
-what are the side effects?
Sulphasalazine
a combination of sulphapyridine (a sulphonamide) and 5-ASA many side-effects are due to the sulphapyridine moiety: rashes, oligospermia, headache, Heinz body anaemia, megaloblastic anaemia, lung fibrosis other side-effects are common to 5-ASA drugs (see mesalazine)
What is mesalazine? why is the preferable to sulphasalazine in some cases?
Mesalazine
a delayed release form of 5-ASA sulphapyridine side-effects seen in patients taking sulphasalazine are avoided mesalazine is still however associated with side-effects such as GI upset, headache, agranulocytosis, pancreatitis*, interstitial nephritis
What haematological condition is assoc. with aminosalicylates?
Aminosalicylates are associated with a variety of haematological adverse effects, including agranulocytosis - FBC is a key investigation in an unwell patient taking them.
when should a diagnosis of IBS be considered?
The diagnosis of IBS should be considered if the patient has had the following for at least 6 months:
Abdominal pain, and/or Bloating, and/or Change in bowel habit
When should a positive diagnosis of IBS be made?
positive diagnosis of IBS should be made if the patient has abdominal pain relieved by defecation or associated with altered bowel frequency stool form, in addition to 2 of the following 4 symptoms:
altered stool passage (straining, urgency, incomplete evacuation) abdominal bloating (more common in women than men), distension, tension or hardness symptoms made worse by eating passage of mucus
Features such as lethargy, nausea, backache and bladder symptoms may also support the diagnosis
What red flag features should be enquired about for ibs? 4
Red flag features should be enquired about:
rectal bleeding unexplained/unintentional weight loss family history of bowel or ovarian cancer onset after 60 years of age
what are 4 red flag features to enquire about when considering IBS
Red flag features should be enquired about:
rectal bleeding unexplained/unintentional weight loss family history of bowel or ovarian cancer onset after 60 years of age
Describe the first line management for IBS
The management of irritable bowel syndrome (IBS) is often difficult and varies considerably between patients. NICE updated it’s guidelines in 2015.
First-line pharmacological treatment - according to predominant symptom
pain: antispasmodic agents constipation: laxatives but avoid lactulose diarrhoea: loperamide is first-line
What could be considered for diarrhoea not responding to conventional laxatives?
For patients with constipation who are not responding to conventional laxatives linaclotide may be considered, if:
optimal or maximum tolerated doses of previous laxatives from different classes have not helped and they have had constipation for at least 12 months
what is the second-line pharmacological treatment for IBS? what is an alternative management option?
Second-line pharmacological treatment
low-dose tricyclic antidepressants (e.g. amitriptyline 5-10 mg) are used in preference to selective serotonin reuptake inhibitors
Other management options
psychological interventions - if symptoms do not respond to pharmacological treatments after 12 months and who develop a continuing symptom profile (refractory IBS), consider referring for cognitive behavioural therapy, hypnotherapy or psychological therapy complementary and alternative medicines: 'do not encourage use of acupuncture or reflexology for the treatment of IBS'
Give 10 pointers for general dietary advice in ibs?
General dietary advice
have regular meals and take time to eat avoid missing meals or leaving long gaps between eating drink at least 8 cups of fluid per day, especially water or other non-caffeinated drinks such as herbal teas restrict tea and coffee to 3 cups per day reduce intake of alcohol and fizzy drinks consider limiting intake of high-fibre food (for example, wholemeal or high-fibre flour and breads, cereals high in bran, and whole grains such as brown rice) reduce intake of 'resistant starch' often found in processed foods limit fresh fruit to 3 portions per day for diarrhoea, avoid sorbitol for wind and bloating consider increasing intake of oats (for example, oat-based breakfast cereal or porridge) and linseeds (up to one tablespoon per day).
what is angiodysplasia? what does it predispose to? what is it thought to be associated with? who is this seen in?
Angiodysplasia is a vascular deformity of the gastrointestinal tract which predisposes to bleeding and iron deficiency anaemia.
There is thought to be an association with aortic stenosis, although this is debated. Angiodysplasia is generally seen in elderly patients
What features of angiodysplasia are seen on blood tests and clinically?
Features
anaemia
gastrointestinal (GI) bleeding
if upper GI then may be melena
if lower GI then may present as brisk, fresh red PR bleeding
What is the diagnosis and management of angiodysplasia
Diagnosis
colonoscopy mesenteric angiography if acutely bleeding
Management
endoscopic cautery or argon plasma coagulation antifibrinolytics e.g. Tranexamic acid oestrogens may also be used
What is bile acid malabsorption? what may this be caused by (primary and 3 secondary causes)? what can this lead to?
Bile-acid malabsorption is a cause of chronic diarrhoea. This may be primary, due to excessive production of bile acid, or secondary to an underlying gastrointestinal disorder causing reduced bile acid absorption. It can lead to steatorrhoea and vitamin A, D, E, K malabsorption.
Secondary causes are often seen in patients with ileal disease, such as with Crohn’s. Other secondary causes include:
cholecystectomy coeliac disease small intestinal bacterial overgrowth
What is the investigation and management of bile acid malabsorption?
Investigation
the test of choice is SeHCAT nuclear medicine test using a gamma-emitting selenium molecule in selenium homocholic acid taurine or tauroselcholic acid (SeHCAT) scans are done 7 days apart to assess the retention/loss of radiolabelled 75SeHCAT
Management
bile acid sequestrants e.g. cholestyramine
What is cholestyramine? what is this used for? what are the adverse effects?
Cholestyramine is a bile acid sequestrant used in the management of hyperlipidaemia. It decreases bile acid reabsorption in the small intestine, therefore upregulating the amount of cholesterol that is converted to bile acid. The main effect it has on the lipid profile is to reduce LDL cholesterol. It is also occasionally used in Crohn’s disease for treatment diarrhoea following bowel resection.
Adverse effects
abdominal cramps and constipation decreases absorption of fat-soluble vitamins cholesterol gallstones may raise level of triglyceride
Diverticulosis:
-What is this caused by? where in the GI tract is affected?
-what are 2 risk factors?
-How can diverticulosis present?
Diverticulosis is an extremely common disorder characterised by multiple outpouchings of the bowel wall, most commonly in the sigmoid colon. Strictly speaking the term diverticular disease is reserved for patients who are symptomatic - diverticulosis is the more accurate term for diverticula being present.
Risk factors
increasing age low-fibre diet
Diverticulosis can present in a number of ways:
painful diverticular disease: altered bowel habit, colicky left sided abdominal pain. A high fibre diet is usually recommended to minimise symptoms diverticulitis
what is diverticulitis? what is the classical presentation? 6
One of the diverticular become infected. The classical presentation is:
left iliac fossa pain and tenderness anorexia, nausea and vomiting diarrhoea features of infection (pyrexia, raised WBC and CRP)
What is the management of diverticulitis?
Management:
mild attacks can be treated with oral antibiotics more significant episodes are managed in hospital. Patients are made nil by mouth, intravenous fluids and intravenous antibiotics (typical a cephalosporin + metronidazole) are given
Give 4 complications of diverticulitis?
Complications of diverticulitis include:
abscess formation peritonitis obstruction perforation
What are the three main conditions of ischaemia to the lower GI tract?
Ischaemia to the lower gastrointestinal tract can result in a variety of clinical conditions. Whilst there is no standard classification it can be useful to separate cases into 3 main conditions
acute mesenteric ischaemia chronic mesenteric ischaemia ischaemic colitis
what are 5 common predisposing factors of lower gi ischaemia?
Common predisposing factors
increasing age atrial fibrillation - particularly for mesenteric ischaemia other causes of emboli: endocarditis, malignancy cardiovascular disease risk factors: smoking, hypertension, diabetes cocaine: ischaemic colitis is sometimes seen in young patients following cocaine use
what are 5 features of ischaemic bowel?
Common features
abdominal pain - in acute mesenteric ischaemia this is often of sudden onset, severe and out-of-keeping with physical exam findings rectal bleeding diarrhoea fever bloods typically show an elevated white blood cell count associated with a lactic acidosis
what investigation is used for the diagnosis of ischaemic bowel?
Diagnosis
CT is the investigation of choice
what is acute mesenteric ischaemia usually caused by?
Acute mesenteric ischaemia is typically caused by an embolism resulting in occlusion of an artery which supplies the small bowel, for example the superior mesenteric artery. Classically patients have a history of atrial fibrillation.
What is chronic mesenteric ischaemia?
Chronic mesenteric ischaemia is a relatively rare clinical diagnosis due to it’s non-specific features and may be thought of as ‘intestinal angina’. Colickly, intermittent abdominal pain occurs.
what is ischaemic colitis? where is this most likely to occur?
ischaemic colitis describes an acute but transient compromise in the blood flow to the large bowel. This may lead to inflammation, ulceration and haemorrhage. It is more likely to occur in ‘watershed’ areas such as the splenic flexure that are located at the borders of the territory supplied by the superior and inferior mesenteric arteries.
What are the investigations for ischaemic colitis? whart is the management?
nvestigations
'thumbprinting' may be seen on abdominal x-ray due to mucosal oedema/haemorrhage
Management
- usually supportive
- surgery may be required in a minority of cases if conservative measures fail. Indications would include generalised peritonitis, perforation or ongoing haemorrhage
What is c. diff?
-what are the risk factors?
Clostridioides difficile is a Gram positive rod often encountered in hospital practice. It produces an exotoxin which causes intestinal damage leading to a syndrome called pseudomembranous colitis. C. difficile develops when the normal gut flora are suppressed by broad-spectrum antibiotics. Clindamycin is historically associated with causing C. difficile but the aetiology has evolved significantly over the past 10 years. Second and third-generation cephalosporins are now the leading cause of C. difficile.
Other than antibiotics, risk factors include:
proton pump inhibitors
What is the pathophysiology of c. diff?
Pathophysiology
anaerobic gram-positive, spore-forming, toxin-producing bacillus transmission: via the faecal-oral route by ingestion of spores releases two exotoxins (toxin A and toxin B) that act on intestinal epithelial cells and inflammatory cells resulting in colitis
Give 4 clinical features of c. diff?
Features
diarrhoea abdominal pain a raised white blood cell count (WCC) is characteristic if severe toxic megacolon may develop
How do you characterise mild c. diff?
Normal WCC
How do you characterise moderate c. diff?
↑ WCC ( < 15 x 109/L)
Typically 3-5 loose stools per day
How do you characterise moderate c. diff?
↑ WCC ( > 15 x 109/L)
or an acutely ↑ creatinine (> 50% above baseline)
or a temperature > 38.5°C
or evidence of severe colitis(abdominal or radiological signs)
How do you characterise severe c. diff?
Hypotension
Partial or complete ileus
Toxic megacolon, or CT evidence of severe disease
HOw is c. diff diagnosis made?
Diagnosis
is made by detecting C. difficile toxin (CDT) in the stool C. difficile antigen positivity only shows exposure to the bacteria, rather than current infection
