Week 13 - Coeliac, Colorectal cancer, Diverticular Disease, Colitis, Diarrhoea, Intestinal obstruction, IBS, ischaemia and gastroenteritis Flashcards
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What is coeliac disease
It is an autoimmune condition triggered by eating gluten.
Who do we always test for coeliac disease
Always test new cases of type 1 diabetes and autoimmune thyroid disease for coeliac even if they do not have symptoms.
What do the antibodies in coeliac disease target and what does this lead to
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Epithelial cells in the small intestine, leading to inflammation
What are the three antibodies particularly related to coeliac disease
Anti-tissue transglutaminase antibodies (anti-TTG)
Anti-endomysial antibodies(anti-EMA)
Anti-deamidated gliadin peptide antibodies(anti-DGP)
Where does this inflammation affect
The small bowel, particularly the jejunum. The surface of the small intestine is inverted in projections called villi which increase the surface area and help with nutrient absorption.
Coeliac disease causes what to happen to the intestinal villi and what does this result in
Coeliac disease causes atrophy of the intestinal villi, resulting in malabsorption
What are the HLA genotypes that coeliac disease is associated with
HLA-DQ2
HLADQ8
What is the presentation of coeliac disease
Often asymptomatic and is under-diagnosed, so have a low threshold for testing. Presenting symptoms include:
failure to thrive in young children
Diarrhoea
Bloating
Fatigue
Weight loss
Mouth ulcers
What is the rash seen in coeliac disease and where is it found
Dermatitis herpetiformis is an itchy blistering skin rash, typically on the abdomen, caused by coeliac disease
What occurs secondary to malabsorption and deficiency of iron, B12 and folate
Anaemia
What are the neurological symptoms that coeliac disease can present with
Peripheral neuropathy
Cerebelar ataxia
Epilepsy
What must the patient do when being investigated for gluten intolerance
Patient must continue to eat gluten. Antibodies and histology may be normal if the patient is gluten free.
What are the first line blood tests done for coeliac disease?
Total immunoglobulin A levels (to exclude IgA deficiency)
Anti-tissue transglutaminase antibodies (anti-TTG)
What is the second line option where there is doubt
Anti-endomysial antibodies (anti-EMA)
How is the diagnosis of coeliac disease confirmed
Diagnosis is confirmed by endoscopy and jejunal biopsy
What are the typical biopsy findings
Crypt hyperplasia
Villous atrophy
How is Coeliac disease managed
A lifelong gluten free diet should completely resolve the symptoms.
What are the complications of coeliac disease?
Nutritional deficiencies
Anaemia
Osteoporosis
Hyposplenism (with immunodeficiency, particularly to encapsulated bacteria such as Streptococcus pneumoniae)
Ulcerative jejunitis
Enteropathy-associated T-cell lymphoma (EATL)
Non-Hodgkin lymphoma
Small bowel adenocarcinoma
What are the factors that increase the risk of colorectal cancer?
family history of bowel cancer
FAP or HNPCC
Crohn’s disease or ulcerative colitis
Increased age
Diet
Obesity and sedentary lifestyle
Alcohol and smoking
What is FAP
An autosomal dominant condition involving malfunctioning of the tumour suppressor genes called APC. It results in many polyps (adenomas) developing along the large intestine.
What is it called when patients get their entire large intestine removed?
Panproctocolectomy
What is HNPCC also known as
Lynch Syndorme
What is HNPCC
An autosomal dominant condition that results from mutations in DNA mismatch repair genes. Patients are at higher risk of cancers, but particularly colorectal cancer
What are the red flags to look out for when considering bowel cancer
changes in bowel habits
Unexplained weight loss
Rectal bleeding
Unexplained abdominal pain
Iron deficiency anaemia
Abdominal or rectal mass on examination.
What are the NICE guidelines for the two week wait for colorectal cancer
over 40 yrs with abdominal pain and unexplained weight loss
Over 50 yrs with unexplained rectal bleeding
Over 60 yrs with a change in bowel habit or iron deficiency anaemia
What is a FIT test
Faecal immunochemical test - look specially for the amount of human haemoglobin in the still.
What is the screening programme used in England
In England, FIT tests are used for bowel cancer screening, people aged 60-74 are sent a home FIT test to do every 2 years. If the results are positive they are sent for a colonoscopy
What is the gold standard investigation for colorectal cancer
Colonoscopy - it involves an endoscopy to visualise the entire large bowel.
What does a staging CT scan involve
Involved a full CT thorax, abdomen and pelvis (CT TAP). It is used to look for metastasis and other cancers. It may be used after a diagnosis of colorectal cancer
What is the tumour marker blood test for bowel cancer
Carcinoembryonic antigen (CEA). This is not helpful in screening, but it may be used for predicting relapse in patients previously treated for bowel cancer.
What is low anterior resection syndrome
May occur after resection of a portion of bowel from the rectum, with anastomosis between the colon and rectum. It can result in a number of symptoms including:
urgency and frequency of bowel movements
Faecal incontinence
Difficulty controlling flatulence
What is the follow up following curative surgery - what does this include
serum CEA
CT TAP
What is the first line constipation drug for children
Movicol is first line laxative for children
What is a diverticulum
Is a pouch or pocket in the bowel wall, usually ranging in size from 0.5-1cm.
What does diverticulosis refer to
The presence of diverticula, without inflammation or infection.
What is diverticulitis
Refers to inflammation and infection of diverticula
Why do diverticula not form in the rectum
Because it has an outer longitudinal muscle layer that completely surrounds the diameter of the recutm, adding extra support.
Where does diverticulosis most commonly affect in the bowel
The sigmoid colon, however it can affect the entire large intestine in some patients.
What increases the risk of getting diverticulosis
Increased age, low fibre diets, obesity and the use of NSAIDs.
How is diverticulosis often diagnosed
Often diagnosed incidentally on colonoscopy or CT scans. Treatment is not necessary where the patient is asymptomatic. However, advice regarding a high fibre diet and weight loss is appropriate
What are the symptoms of diverticulosis
May cause lower left abdominal pain, constipation or rectal bleeding.
What is the management of diverticulosis
Increased fibre in the diet and bulk-forming laxatives. Stimulant laxatives should be avoided.
What does acute diverticulitis present with:
pain and tenderness in LIF
Fever
Diarrhoea
Nausea and vomiting
Rectal bleeding
Palpable abdominal mass
Raised inflammatory markers
What is the management of uncomplicated diverticulitis in primary care:
oral co-amoxiclav for at least 5 days
Analgesia - avoid NSAIDs
Only taking clear liquids and avoid solid food
Follow up within 2 days
What happens to patients with severe pain or complications with diverticulitis
They go to hospital and receive;
NBM
IV antibiotics
Analgesia
IV fluids
Urgent investigations (CT scan)
Urgent surgery may be required for complications.
What are the complications of acute diverticulitis
perforation
Peritonitis
Peridiverticular abbess
Large haemorrhage requiring blood transfusions
Fistula
Ileus / obstruction
what is the treatment for infective colitis
rehydrate with oral or IV solution keeping a close eye on electrolytes and replace as required.
what is diarrhoea defined as
the passage of a lose liquid stool
what kind of diarrhoea is always pathological
bloody diarrhoea is always pathological and will nearly always be caused by some form of colitis
what may diarrhoea that develops in the hosptial be due to
C.difficile infection
what is the named endocrine cause of diarrhoea
hyperyhyroidism
what are the 3 causes of infective diarrhoea
bacterial
viral
parasitic
what are the 4 types of bacterial diarrhoea
- e coli (most common)
- salmonella
- shigella
- campylobacter
what are the 2 viral causes of infective diarrhoea
Rotovirus – this is THE most common cause of diarrhoea
Norovirus – an umbrella term for a range of similar viruses
what are the 3 causes for parasitic infective diarrhoea
Amoebic dysentery – caused by Entamoeba histolytica
Giardiasis – caused by Giardia
Cryptosporidium
what are the 3 common types of diarrhoea when travelling
cholera - highly dangerous
e.coli
guarduasus
how does clindamycin cause diarrhoea
this is a broad spectrum antibiotic (and the same affect may be seen in other broad spectrum ABs)
it will kill almost all bacteria in the gut. the problem is that this then allows resistant C.difficile to proliferate and cause diarrhoea
how does erythromycin cause diarrhoea
this increases gut motility, it is sometimes even used to treat constipation
how does penicillin cause diarrhoea
breakdown products of this act as an osmotic laxative
how does tetracylcin cause diarrhoea
this has an effect on fat absorption and thus leads to diarrhoea
how does neomycin lead to diarrhoea
Neomycin – this affects bile salt absorption and thus the bile salts act as an osmotic laxative and draw fluid into the lumen.
what metabolic disorders cause diarrhoea
hyperthyroidism
thyrotoxicosis
anxiety
peptides secreted by unsusual tumours
what are the 3 small bowel diseases that cause diarrhoea
Crohn’s disease
coeliac disease
blind loop syndrome
what are the 5 large bowel disease causes of diarrhoea
UC
colon cancer
IBS
spurious
polyps and diverticular disease
what are the investigations used in the queiry of diarrhoea cause
FBC – to check for leukocytosis (for infective causes and colitis) and anaemia
Anti α-gliadin Abs – test for coeliac’s disease
Thyroid function tests – check for hyperthyroidism
Stool culture – check for infections; don’t forget microscopy for parasites
Proctoscopy / sigmoidoscopy – cancer / colitis and polyps
Flexible sigmoidoscopy / colonoscopy – if protoscopy does not deliver enough detail.
Small bowel enema – can see Crohn’s coeliac’s and Whipple’s disease
ERCP – can see pancreatic insufficiency.
what is ileus
a condition affecting the small bowel, where the normal peristalsis that pushes the contents along the length of the intestines, temprrarily stops.
what is the term used to describe a functional obstruction of the large bowel
a pseudo-obstruction
what are the causes of ileus
Injury to the bowel
Handling of the bowel during surgery
Inflammation or infection in, or nearby, the bowel (e.g., peritonitis, appendicitis, pancreatitis or pneumonia)
Electrolyte imbalance (e.g., hypokalaemia or hyponatraemia)
what is the most common time you will see ileus
following abdominal surgery. this usually resolves with supportive care within a few days
what are the signs and symptoms of ileus
Vomiting (particularly green bilious vomiting)
Abdominal distention
Diffuse abdominal pain
Absolute constipation and lack of flatulence
Absent bowel sounds (as opposed to the “tinkling” bowel sounds of mechanical obstruction)
what is the management of ileus
the ileus will usually resolve with treatment of the underlying cause. management involves supportive care.
what does supportive care for ileus include
Nil by mouth or limited sips of water
NG tube if vomiting
IV fluids to prevent dehydration and correct the electrolyte imbalances
Mobilisation to helps stimulate peristalsis
Total parenteral nutrition (TPN) may be required whilst waiting for the bowel to regain function
what kind of diagnosis is IBS
a diagnosis of exclusion
what are the red flag symptoms of IBS that would suggest a more serious underlying cause
Rectal bleeding
Age >50 at first presentation
Family history of bowel or ovarian cancer
Iron deficiency anaemia
Unexplained weight gain or weight loss
what is the differential diagnosis for IBS
Bowel cancer
Ovarian Cancer
Coeliac disease
Inflammatory bowel disease
Infective colitis
what are the general symptoms of IBS
nausea alone
vomiting alone
bleching
chest pain
abdominal discomfort and bloating
young patients
frequent bowel actions
no weight gain
what are the gynaecological manifestations of IBS
painful periods and pain after sex
prementrual tension
what are the urinary symptoms associated with IBS
frequency
urgency
nocturia
incomplete emptying of the bladder
what is the most common cause of GI referral in the UK
IBS
are men or women more affected
women are 2-3 times more affected
what is the Rome criteria used for
set of criteria that attempt to define the symptoms of functional bowel disorders. using the criteria, you can put sufferers into different categories in an attempt to tailor their treatments
what does the Rome criteria state
the criteria state that in the preceeding 12 months, there should be at least 12 consecutive weeks of abdominal pain and discomfort with at least two of the following:
- pain relieved on defecation
- onset associated with a change in frequency of stool
- onset associated with change in appearance of the stool
what are the 5 types of functional bowel disorders
IBS
functional abdominal bloating
functional constipation
functional diarrhoea
functional abdominal pain
what is neurosis
a condition that causes psychological distress, but unlike psychosis it does not prevent or affect rational thought. In neurotisism, symptoms are interpreted more negatively than the general population
what sort of pain will most IBS sufferers have
colicky LLQ pain that is relieved on defecation
they also tend to have diarrhoea and constipation regularly
what do tests and investigations do in IBS
they do not confirm the diagnosis but they can rule out other conditions
often a diagnosis can be made based on history and clinical diagnosis alone without the need for further investigations
what does any sign of mucosal inflammation mean
this means it is NOT IBS
what is a sign of long term laxative use
pigmented mucosa in the rectum (melanosis coli)
what is the most popular theory of pathophysiology behind iBS
neuromuscular dysfunction
basically this theory states that patients that have IBS have some sort of neuromuscular abnormalities that affect normal gut motility. the problem is there isnt much evidence for this. there is some evidence that shows there is increased colonic activity in those with IBD, but how this relates to symptoms is uncertain.
what is the visceral hypersensitivity theory
this is another popular theory and states that nervous sensitivity in the gut is somehow enhanced in people with IBD. This would make sense, because many IBD patients report increased pain response to rectal distension (e.g. during the colonoscopy). The sensitivity appears to be visceral specific – i.e. there is no increased cutaneous hypersensitivity. It is also uncertain as to whether this hypersensitivity exists as a result of abnormal mechanoceptor functioning, or as a result of abnormal sensory processing by the brain and spinal chord.
in 50% of IBS conditions, what relieves the symptoms
a placebo
what is given for persistent diarrhoea
loperamide - 2mg
what is given for persistent constipation
osmotic laxative - movicol, lactulose
avoiding stimulant laxatives
what is mesenteric ischaemia caused by
lack of blood flow through the mesenteric vessels supplying the intestines, resulting in intestinal ischaemia
what are the three main branches of the abdominal aorta that supply the abdominal organs
coeliac artery
superior mesenteric artery
inferior mesenteric artery
what does the foregut include
stomach, part of the duodenum, biliary system, liver, pancreas and spleen
what is the foregut supplied by
the coeliac artery
what is the midgut formed of
distal part of the duodenum, to the first half of the tranverse colon.
what is the midgut supplied by
the superior mesenteric artery
what is the hindgut made up of
second half of the transverse colon to the rectum
what is the hindgut suppled by
inferior mesenteric artery
what is chronic mesenteric ischaemia
result of narrowing of the mesenteric blood vessels by atherosclerosis.
this results in intermittent abdominal pain, when the blood supply cannot keep up with the demand. similar to angina
what is the typical triad presentation of chronic mesenteric ischaemia
Central colicky abdominal pain after eating (starting around 30 minutes after eating and lasting 1-2 hours)
Weight loss (due to food avoidance, as this causes pain)
Abdominal bruit may be heard on auscultation
what are the risk factors for chronic mesenteric ischaemia
Increased age
Family history
Smoking
Diabetes
Hypertension
Raised cholesterol
what is diagnosis of chronic mesenteric ischaemia confirmed with
CT angiography
what does management of chronic mesenteric ischaemia include
reducing modifiable risk factors
secondary prevention - statins and antiplatelets
revascularisation to improve the blood flow to the intestines
what is acute mesenteric ischaemia
typically caused by a rapid blockage in blood flow through the superior mesenteric artery
this is usually caused by a thrombus
what is a key risk factor of acute mesenteric ischaemia
atrial fibrillation where a thrombus forms in the left atrium, then it mobilises down the aorta to the SMA where it becomes stuck and cuts off the blood supply
what is the diagnostic test of choice for acute mesenteric ischaemia
Contrast CT
patients will have metabolic acidosis and raised lactate level due to ischaemia
what is the mortality rate for acute mesenteric ischaemia
very high mortality rate - 50%
what is acute gastritis
is stomach inflammation and presents with epigastric discomfort, nausea and vomiting
what are the most common causes of gastroenteritis
viruses.
what specific viruses cause gastroenteritis
Rotavirus
Norovirus
Adenovirus (tends to cause respiratory symptoms)
what is E.coli
produces the Shiga toxin. this leads to abdominal cramps, bloody diarrhoea and vomiting.
what does e.coli lead to when it produces the Shiga toxin
destroys red blood cells, leading to haemolytic uraemic syndrome (HUS)
why are antibiotics avoided if E.coli is suspected
because the use of antibiotics increases the risk of haemolytic uraemic syndrome
what is a common cause of traveller’s diarrhoea
Campylobacter
how is Campylobacter spread
Raw or improperly cooked poultry
Untreated water
Unpasteurised milk
how long is the incubation period for campylobacter
Incubation is usually 2 to 5 days. Symptoms resolve after 3 to 6 days
what are the symptoms of campylobacter
Abdominal cramps
Diarrhoea often with blood
Vomiting
Fever
what is first line for campylobacter
clarithromycin
when may you come across bacillus cereus
with infective endocarditis in IV drug users where heroin is contaminated.
what is the most common cause of infective endocarditis in intravenous drug users
staph aureus
eating raw or undercooked pork can cause what kind of infection
Yersinia enterocolitica is a gram-negative bacillus.
what is giardiasis treated with
Treatment is with tinidazole or metronidazole.
is food poisoning a notifiable disease
yes - the UKHSA should be notified.
what kind of drugs are avoided in viral gastroenteritis
antidiarrhoeal drugs and antiemetics are they worsen the condition.
The NICE Clinical Knowledge Summaries (updated June 2023) suggest antidiarrhoeal drugs may be helpful in mild-moderate diarrhoea but should be avoided with E. coli 0157, shigella or bloody diarrhoea.
