GI Flashcards
What is inflammatory bowel disease?
An umbrella term for the two main diseases causing inflammation of the GI tract.
What are the two main causes of IBD?
Ulcerative colitis and Crohn’s disease
What is Crohn’s diease?
Transmural inflammation of the GI tract (anywhere from mouth to anus).
Where is the most commonly affected area of Crohn’s?
Terminal ileum and Colon
Describe the epidemiology of Crohn’s?
- Has a peak onset in early life (20-40 years).
- More common in female than male
What genetic mutations can cause Crohn’s?
CARD15 and NOD2 mutation
What pathogens can cause Crohn’s?
- Mycobacterium paratuberculosis,
- Listeria
- Pseudomonas
What is thought to cause Crohn’s disease?
- Immune system is thought to be triggered by a pathogen. These pathogens get through the wall due to defect
- This causes the immune system to target the foreign pathogen. The immune cells invade deep into the mucosa and organise themselves into granulomas eventually forming ulcer.
- These ulcers go through all layers known as TRANSMURAL this occurs in patches known as skip lesions
What is the endoscopic appearance of Crohn’s?
Cobblestone appearance
What are the signs of Crohn’s?
- Abdominal tenderness
- Fever
- Mouth ulcers
- Rectal examination will show blood, skin tags, fissures and fistulas
What are the symptoms of Crohn’s?
- Weight loss
- Diarrhoea
- Abdominal pain (most common in RLQ where the ileum is)
- Lethargy and malaise also symptom
What are the investigations for Crohn’s?
- Faecal calprotectin (released by intestines when inflamed)
- C- reactive protein is a good indication of current inflammation
What is the diagnostic investigation for Crohn’s and what will it show?
Colonoscopy- will show mucosal inflammation (deep ulcers, skip lesions and cobblestone appearance)
Histology will show transmural inflammation with granulomas and goblet cells
What is the management for inducing remission in Crohn’s?
- Elemental diet (nutrients in pre digested form)
- First-line is glucocorticoids e.g., prednisolone and hydrocortisone)
- Immunosuppressants- should not be used alone
- Biological therapy
- Adjunct use antibiotics
What are some immunosuppressants used to treat Crohn’s? Levels of what should be measured before using them?
- Azathioprine
- Methotrexate
- Mercaptopurine
Levels of Thiopurine methyltransferase should be measured before using
What are the biological therapies used to treat Crohn’s?
Infliximab and Adalimumab
How would you maintain remission in Crohn’s?
- First line= Azathioprine or mercaptopurine
- Second line- Methotrexate with Infliximab
When and what surgery could be used to treat Crohn’s?
- When distal ileum is inflamed can surgically resect the area to prevent flare ups
- Also used to treat strictures and fistulas
What are the key things to remember for Crohn’s?
NESTS
N- No blood or mucus
E- entire GI tract
S- Skip lesions
T- Terminal ileum and transmural
S- Smoking is a big risk factor
What is Ulcerative colitis?
A type of IBD that typically involves the rectum and variable lengths of the colon. Will never spread beyond the ileocecal valve
Describe the epidemiology of UC?
- Bimodal peak at 15-25 and 55-70
- More common in non-smokers
What is the gene implicated in UC?
HLA-B27
What are some other risk factors for UC?
- Non smoker
- NSAIDs
- Chronic stress/depression
Describe the pathophysiology of UC?
- Ulcers tend to form along the inner surface or lumen of the large intestine and rectum
- Thought to be autoimmune in nature cytotoxic T cells attack the lining of the colon
- Also thought that patients have higher proportion of gut bacteria that release sulphides
Describe the pathophysiology of UC?
- Ulcers tend to form along the inner surface or lumen of the large intestine and rectum
- Thought to be autoimmune in nature cytotoxic T cells attack the lining of the colon
- Also thought that patients have higher proportion of gut bacteria that release sulphides
What antibodies are found in patients with UC?
p-ANCAs -perinuclear antineutrophilic cytoplasmic antibodies) in their blood - antibodies that target antigens in the body’s own neutrophil
What are the signs of UC?
- Abdominal tenderness
- Fever - in acute UC
- Tachycardia - in acute severe UC
- Fresh blood on rectal examination
What are some cutaneous signs of UC?
- Erythema nodosum - inflammatory disorder affecting subcutaneous fat.
- Pyoderma gangrenosum - rapidly enlarging, very painful ulcer.
What are the symptoms of UC?
- Diarrhoea
- Blood and mucus in stool
- LLQ pain
- Weight loss
- Cramping rectal pain
What investigations would you do for UC?
- Faecal calprotectin
- LFT to screen for PSC
- Raised C-reactive protein
What is the gold standard for UC and what would it show?
Colonoscopy and biopsy
Would show:
-shallow ulceration
- No inflammation beyond submucosa
- Crypt abscesses
- Goblet cell depletion
What is the scoring system used to test the severity of UC?
Truelove and Witts’ severity index
What is the management for inducing remission in mild UC?
- First line: Aminosalicylate (mesalazine)
- Second line corticosteroid (prednisolone)
What is the management for inducing remission in severe UC?
- First line: IV corticosteroid hydrocortisone
- Second line IV ciclosporin
How would you maintain remission in UC?
- Aminosalicylate, azathioprine, mercaptopurine
-May use biological therapy e.g., Infliximab if nothing else is working
What are the surgical options for UC?
- Removal of the colon and rectum (panproctocolectomy)
- Left with ileostomy or or J-pouch this is where small intestine is used to make rectum
Surgery will be curative
What is a complication of UC?
- STI of stoma
- Toxic megacolon
- Perforation
- Colonic adenocarcinoma
What % of patients with UC will develop colonic adenocarcinoma?
3-5%
What are the key things to remember for UC?
CLOSEUP
C- Continuous inflammation
L- Limited to colon and rectum
O- only superficial
S- Smoking protects
E- Excrete blood and mucus
U- Use Aminosalicylate
P- PSC
What are the extra intestinal signs of IBD?
A PIE SAC
- Ankylosing spondylitis (HLA B27!)
- Pyoderma gangrenosum
- Iritis (aka anterior uveitis)
- Erythema nodosum
- Sclerosing cholangitis
- Aphthous ulcers / amyloidosis
- Clubbing
What is irritable bowel syndrome/
A chronic condition characterised by abdominal pain associated with bowel dysfunction. It is a functional bowel disorder. Tom Coles suffers with it.
What are the 3 types of IBS?
IBS-C- with constipation
IBS-D with constipation and diarrhoea
IBS-M with both
(tom has the diarrhoea one)
What is the epidemiology of IBS?
- It affects women more than men
- More common in younger adults <40 years
What are the risk factors for worse symptoms of IBS?
- Acute gastroenteritis
- Stress
- Menstruation
What causes the pain in IBS?
- People with IBS often have visceral hypersensitivity which means the sensory nerve endings of the intestinal walls have a strong response to stimuli e.g., stretch after a meal
What causes the abnormal gut motility in IBS?
- Eating foods such as short chain carbohydrates can act to draw water across the GI wall and into the lumen
- The increased visceral sensitivity can also cause the smooth muscle to spasm creating diarrhoea if water is not absorbed properly
- In addition, the unabsorbed short-chain carbohydrates are often metabolised by gastrointestinal bacterial flora which produce gas that could trigger more bloating, spasm, or pain.
What can alter the gut reactivity?
environmental (personal life stresses or abuse)
luminal (certain foods, bacterial overgrowth or toxins, or gut distension or inflammation)
What are the symptoms of IBS?
- Fluctuating bowel habit
- Diarrhoea
- Constipation
- Abdominal pain: worse after eating and better after opening of bowels
What are the diagnostic criteria for IBS?
- Abdominal pain relieved on opening bowel
And two of - Abnormal stool passage
- Bloating
- Worse after eating
- PR mucus
What tests would you perform for IBS to rule out other causes?
- FBC, CRP would be normal
- Normal faecal calprotectin
- Negative coeliac disease (anti-TTG antibodies)
- Cancer is ruled out on colonoscopy
What is the management for IBS?
- Loperamidefor diarrhoea
- Laxatives for constipation.
What is coeliac disease?
A systemic autoimmune disorder that affects the small intestine that is triggered by the ingestion of gluten peptides
What are the genes that can cause coeliac disease?
HLA-DQ2
HLA-DQ8
What are the two auto-antibodies associated with coeliac disease?
Anti-TTG
Anti-EMA
These antibodies relate to disease activity and will rise with more active disease and may disappear with effective treatment.
What are some risk factors for coeliac disease?
T1DM
IgA deficiency
What happens in someone with coeliac disease?
Inflammation affects the small intestine particularly the jejunum. This causes atrophy of the intestinal villi and crypt hypertrophy
These villi are used to help absorb nutrients so coeliac will result in malabsorption.
What area of the intestine is most affected by coeliac disease?
Jejunum
What are the extra intestinal symptoms of coeliac disease?
- Dermatitis herpetiformis
- Angular stomatitis
- Mouth ulcers
- failure to thrive
What are the intestinal symptoms of coeliac disease?
- Diarrhoea
- Weight loss
- Bloating
- B12 deficiency
What are the investigations for coeliac disease?
- 1st line raised anti-TTG antibodies
- 2nd line raised anti-EMA
Gold standard- duodenal biopsy villous atrophy, Crypt hyperplasia and intraepithelial lymphocytes
TTG and anti-EMA antibodies are IgA. Some patients have an IgA deficiency. When you test for these antibodies, it is important to test for total Immunoglobulin A levels because if total IgA is low because they have an IgA deficiency then the coeliac test will be negative even when they have coeliacs. In this circumstance, you can test for the IgG version of anti-TTG or anti-EMA antibodies or simply do an endoscopy with biopsies.
What are the complications of untreated coeliac diease?
- Vitamin deficiency
- Anaemia
- Osteoporosis
- Ulcerative jejunitis
- Enteropathy-associated T-cell lymphoma (EATL) of the intestine
- Non-Hodgkin lymphoma (NHL)
- Small bowel adenocarcinoma (rare)
What is gastritis?
Gastritis refers to inflammation of the lining of the stomach associated with mucosal injury.
What are the different ways to classify gastritis?
- Location: Antral or pangastritis
- Time: Acute or chronic
- Type: Erosive or non-erosive
What are the causes acute gastritis?
- H.Pylori infection
- Alcohol abuse
- Stress (critically ill/post surgery)
- NSAIDs
What are the causes of chronic gastritis?
- H.Pylori infection
- Autoimmune gastritis (parietal and intrinsic factor antibodies)
How does H.Pylori cause gastritis?
- It produces urease which converts urea to ammonia and CO2 which is toxic since the ammonia will react with HCL to form ammonium.
- The ammonium will damage the gastric mucosa resulting in less mucus production
What are the clinical manifestations of gastritis?
- Nausea
- Abdominal bloating
- Vomiting
- Epigastric pain
- Indigestion
- Haematemesis- “coffee ground” vomiting and melaena
- Iron deficiency anaemia due to constant bleeding
What is the general investigation for gastritis?
- Endoscopy will show gastric inflammation and atrophy
How would you test for autoimmune gastritis?
Testing for autoimmune gastritis
- Look for anti-IF (intrinsic factor) antibody and anti-parietal cell antibodies
- Raised gastrin levels, reduced pepsinogen
What are the tests for H.Pylori?
- CLO test Urea breath test
- Stool antigen test
Before testing, stop PPI for at least 2 weeks; antibiotics for 4 weeks
How would you treat gastritis not caused by H.Pylori?
- Remove causative agents such as alcohol/NSAIDs
- Reduce stress
- H2 antagonists e.g. ranitidine or cimetidine - to reduce acid release
- PPIs e.g. lansoprazole or omeprazole - to reduce acid release
- Antacids - neutralise acid to relieve symptoms
How do you treat a H.Pylori infection?
Triple threat (PPI and 2 antibiotics) twice a day for 7 days
- 1st line PPI, 1g amoxicillin and clarithromycin 500mg
- If penicillin allergy then give metronidazole 400mg as well as instead
What are the complications of gastritis?
- Peptic ulcers
- Bleeding and anaemia
- MALT lymphoma (mucosa-associated lymphoid tissue)
- Gastric cancer
What is Peptic ulcers disease?
A break in the mucosal lining of the stomach or duodenum more than 5 mm in diameter.
What are more common gastric or duodenal ulcers?
Duodenal ulcers are more common than gastric ulcers.
What is the main cause of PUD?
H.Pylori is responsible for 95% of duodenal ulcers and 75% of gastric ulcers
What drugs can cause PUD?
- NSAIDs inhibit COX enzyme which is needed for prostaglandin synthesis
- SSRIs, steroids and bisphosphonates can also cause as they break down the protective layer
What lifestyle factors can cause PUD?
- Smoking and alcohol: may lead to increased acid.
- Caffeine: may lead to increased acid.
- Stress: may lead to increased acid.
What other health conditions can cause PUD?
- Zollinger-Ellison syndrome:a gastrinoma (tumour) that results in numerous peptic ulcers due to elevated gastrin levels
- Blood type O
- Raised intracranial pressure:causes vagal stimulation which increases acid production (Cushing’s ulcer).
- Severe burn:hypovolaemia secondary to a burn causes reduced perfusion of the stomach leading to necrosis (Curling ulcer)
What are the signs of PUD?
- Hypotension and tachycardia
- Epigastric tenderness
What are the symptoms of PUD?
- Burning epigastric pain
- Nausea
- Hematemesis or melaena- caused by the perforation of an artery
- Indigestion (Dyspepsia)
- Reduced appetite
What is the gold standard test for PUD?
Endoscopy and biopsy. It excludes malignancy. Will not be performed for non-bleeding ulcers
What is used to stratify the risk for a GI bleed?
Glasgow Blatchford score
What factors are considered in the GBS?
- HB
- Urea
- BP
- Gender
- Tachycardia
- Melaena
- Syncope
- Hepatic disease history
- Cardiac failure present
What is the difference in pain onset between a gastric and duodenal ulcer?
Gastric ulcer is worse after eating and duodenal is better 1-2 hours after eating but then worsens 2 hours after
Which artery is perforated in gastric vs duodenal ulcers?
Gastric= Left gastric
Duodenal= Gastroduodenal
What are the signs of perforation in gastric vs duodenal ulcers?
- Gastric= haematemesis and melena
- Duodena= Melaena and haematochezia
How would you treat an active peptic ulcer bleed?
First line:
- IV crystalloid
- Blood transfusion
- Endoscopy
- High dose IV PPI
- Second line
Surgery or embolization (blocking abnormal vessels) by interventional radiology: reserved for cases where adequate haemostasis is not achieved at endoscopy
What are the complications of PUD?
- Perforation: life-threatening as ulcer penetrates the duodenum or stomach into the peritoneal cavity causing peritonitis. May also allow air to collect under the diaphragm and irritate the phrenic nerve causing referred shoulder pain. Requires surgical intervention!
- Gastric outlet obstruction/ pyloric stenosis: caused by obstruction of the pylorus due to an ulcer and subsequent scarring. Presents with abdominal pain, distension, vomiting and nausea after eating
What is GORD?
Reflux of stomach contents into the oesophagus.
How common is GORD?
Has a prevalence as high as 10-20%
What are the lifestyle risk factors for developing GORD?
- Obesity
- Pregnancy
- Smoking
- NSAIDs, caffeine and alcohol
What are the biological risk factors for GORD?
- Hiatus hernia- pushes the stomach up into the diaphragm
- Male sex
- Scleroderma: muscle of the lower oesophageal sphincter is replaced by connective tissue, so it can’t contract properly.
- Zollinger-Ellison syndrome: increased gastrin causes increased HCl secretion
Describe how food normally moves from the oesophagus to the stomach
- Normally food is moved into the stomach via peristalsis. At the gastro-oesophageal junction the sphincter relaxes to allow food to enter the stomach and after entry the sphincter relaxes to prevent reflux.
- If the LOS relaxes inappropriately (due to drop in pressure) then the stomach contents will wash back into the oesophagus and cause acid reflux
Describe the pathophysiology of GORD?
- When there is very low pressure in the oesophagus reflux will persist for longer becoming pathological.
- Persistent acid reflux damages the mucosa causing inflammation. This will eventually lead to oedema and erosion of the mucosa.
What happens to the oesophageal mucosa as GORD progresses?
- The epithelium will become damaged and replaced by scar, making the walls thicker and the lumen narrower
- As there is damage there will be metaplasia of the cells going from stratified squamous to simple columnar (Barret’s oesophagus). This can eventually lead to adenocarcinoma (3-5%)
What are the key symptoms of GORD?
- Heart burn
- Regurgitation which is worse when lying down
What are someo other symptoms of GORD?
- Epigastric pain
- Dysphagia (difficulty swallowing)
- Dyspepsia (indigestion)
- Extra-oesophageal: cough, asthma, dental erosion
What are the initial investigations for GORD in people without red flag symptoms?
- Can be diagnosed based on clinical presentation and based on whether PPI trial would resolve the symptoms
- PH monitoring
What are the the red flag symptoms for GORD?
ALARMS
A- Anaemia
L- Loss of weight
A- Anorexia
R- Recent onset
M- Melaena
S- Swallowing difficulties
When would you refer for 2 week endoscopy? (gord)
Dysphagia or
Age ≥ 55yo with weight loss and 1 of the following:
- Upper Abdo pain
- Reflux
- Dyspepsia (indigestion)
What investigations would you perform for a clinical diagnosis of GORD?
- FBC (anaemia)
- 24-hour pH monitoring (pH <4 for more than 4% of the time is abnormal)
- Upper GI endoscopy
- Manometry (rule out motility disorders)
What are lifestyle changes for managing GORD?
- Weight loss
- Reduce alcohol intake
- Eat smaller meals
- Avoid eating before going to bed (no food 2 hours before bed)
What are the medical managements for GORD
- PPI- this will lower acid production within the stomach
- H2 receptor antagonist e.g., ranitidine reduces stomach acid
- Antacids e.g., Gaviscon
What is the surgical management for GORD?
- Nissen fundoplication: wrapping the fundus of the stomach around the lower oesophagus to tighten the sphincter
What is Barret’s oesophagus defined as?
Barrett’s oesophagus describes metaplasia (transformation of one differentiated cell type to another differentiated cell type) of the lower oesophageal lining from stratified squamous epithelium to mucous secreting columnar epithelium with goblet cells.
Barrett’s is classified as short segment (< 3 cm) and long segment (> 3 cm).
What is appendicitis?
Acute appendicitis is an acute inflammation of the vermiform appendix, most likely due to obstruction of the lumen of the appendix.
What are the different positions of the appendix?
- Most commonly thedescending intraperitoneal or retrocaecal position
- Retrocaecal and pelvic appendicitis are often more difficult to distinguish clinically
What is the epidemiology of appendicitis?
- Appendicitis is the most common acute abdominal condition in the UK requiring surgery
- The highest incidence is between 10-20 years of age
- M>F
What causes appendicitis?
- Normally occurs due to luminal obstruction
- As the appendix continues to secrete mucus the fluid and mucus build up and increase the pressure this causes it to get bigger and push on the visceral nerve fibres causing pain
- This will lead to bacterial overgrowth