GI Flashcards
What does inflammatory bowel disease comprise of? (IBD)
Ulcerative colitis Chron’s disease
Pathophysiology of IBD?
Inflamed intestines Associated with HCAB27 (Seronegative spondyloarthropathy) Has a Bimodal age distribution (15-20, 55+)
Cause of Chron’s disease?
Environmental and genetic - CARD15/NOD2 mutation => strong genetic component - bacteria trigger an immune mediated response (t-cells)
What part of the gut does Chron’s disease affect?
Whole gut Especially terminal ileum and proximal colon (usually rectum is spared)
Risk factors for Chron’s
Family history Jewish HLA-B27 gene Smoking (2x as likely) Caucasian
Pathophysiology of Chron’s
-Characterised by skip lesions (lesions with gaps in between) arising anywhere between the mouth and the anus -End result is transmural inflammation (in all layers) with granuloma formation => resulting in fistulas, strictures and adhesions
Signs and symptoms of Chron’s disease?
Diarrhoea- most significant symptom in adults -Abdominal pain- most significant symptom in kids -Gallstones and kidney stones -Weight loss and lethargy -B12/folate/ Fe deficiency due to malabsorption in small intestine -Apthous mouth ulcers
Extraintestinal manifestations of both Chron’s and Ulcerative Colitis
Eyes:Episcleritis = chrons> Uveitis = UC> Cutaneous: Erythema nodosum Pyoderma gangrenosum Musculoskeletal: Arthritis (most common manifestation in both) Spondylarthritis “spine ache” Osteoporosis Clubbing Also 90% of UC patients have PSC but also sometimes present in patients with Chron’s
Investigations to diagnose Chron’s
-Feacal calprotectein = raised (inflammation in GI tract + differentiates IBD from IBS) -FBC -CRP/ESR -U&Es -Colonoscopy = skip lesions, cobblestone mucosa, deep ulcers -Biopsy = transmural inflammation, granulomas and goblet cells
How to differentiate UC from Chron’s particularly in the peadiatric population?
Serum antibody markers: - pANCA more associated with UC - ASCA more associated with Chron’s
How to differentiate IBD from IBS?
Faecal calprotectin Raised in IBD and not IBS
General management tips for Chron’s
Smoking cessation advice = crucial -Some evidence that NSAIDs and/or combined oral contraceptive pill can increase risk of relapse
Treatment given to induce remission in mild and moderate Chron’s
Elemental diet (alone or with meds, particularly in young people) Mild Chron’s: FIRST LINE : glucocorticoids (PO predinsolone or IV hydrocortisone) SECOND LINE: aminosalicylate (eg mesalazine) Moderate Chron’s: Add in: FIRST LINE: azathioprine or mercaptopurine SECOND LINE: Methotrexate
Treatment for severe Chron’s to induce remission that is unresponsive to conventional therapy
Infliximab or adalimumab as monotherapy or combined with other immunosuppressant
Treatment for Chron’s if it is refractory to medical therapy or disease limited to the distal ileum to induce remission
Surgery
How to classify severity of Chron’s
Mild: - first prevention or - 1 exarcerbation in 12 months Moderate: - >= exarcerbations in 12 months or - glucocorticoid cannot be tapered for management of mild disease Severe: - unresponsive to conventional therapy AND - >= symptoms eg weight loss, fever, severe abdominal pains - usually >3 loose stools per day
How to maintain remission in Chron’s
1st line: azathioprine or metcaptopurine 2nd line: Methotrexate Post surgery: consider azathioprine with or without methotrexate
Frequency of surgery in Chrons patients?
Approx 80% of patients with Chron’s will require surgery but this is not curative as entire bowel can be affected. By removing ‘x’, ‘y’ can flare up.
Complications of Chron’s
Peri-anal abscess Anal fissure Anal fistula Strictures and obstruction
Location of ulcerative colitis
COLON ONLY start at rectum—> sigmoid colon—> proximal colon Never proximally beyond illeocaecal valve Doesn’t affect the anus
Aetiology of ulcerative colitis
Not well understood Autoimmune colitis associated with HCA B27 gene Involves polygenic predisposition and env factors
Risk factors for ulcerative colitis
Family history HLA b27 Caucasian Non-smokers Bimodal age distribution 15-25 and 55-70yrs
Physiopathology of ulcerative colitis
Histopathology will show mucosal and submucosal ulceration as well as crypt abscesses with neutrophil infiltration
Symptoms of ulcerative colitis
Abdominal pain in left lower quadrant -Urgency and tenesmus (pain on defecation) -Bloody mucosy watery Diarrhoea
Investigations to diagnose ulcerative colitis
-Increase in feacal calprotectin -pANCA +ve -FBCs -CSR\ESR - colonoscopy = continuous, “leadpipe sign” - biopsy = raw/red mucosal with widespread shallow ulceration with crypt abscesses and goblet cell depletion
How is disease activity measured in ulcerative colitis patients?
Truelove and Witt’s severity index
Treatment for ulcerative colitis to induce remission
Generally: First line: topical ASAs Second line: Add high-dose oral ASA Third line: Add topical or oral corticosteroid For acute severe colitis admit into hospital and start iV corticosteroids Add ciclosprin if no improvement in 72hr Still no improvement consider surgery
Treatment for maintenance of remission of ulcerative colitis
Low maintainance dose of ASA
Surgery with ulcerative colitis?
Total/partial colectomy is often curative
Complications of ulcerative colitis
Toxic megacolon is the most common complication cause ulcerative colitis deaths
What is Coeliac’s?
Systemic autoimmune T4 hypersensitivity to gluten that effects the small intestine
Pathophysiology of Coeliac’s
Pathogenic component of gluten = gliadin -Once absorbed, it is deamidated by tissue transglutaminase (tTG) -in coeliacs, deamidated peptides are presented by antigen-presenting cells via HLA DQ2 or DQ8 to T helper cells to trigger immune response. -immune activation —> villous atrophy, lymphocyte accumulation and intestinal crypt hyperplasia —> malabsorption
Risk factors for Coeliacs
Family history HLA-DQ2 and HLA-DQ8 Autoimmunity (thyroid disorders + addisons) IgA deficiency Down’s syndrome Turner’s syndrome
Signs and symptoms of coeliacs
Indigestion Diarrhoea or steatorrhoea Bloating and/or constipation Weight loss and fatigue Unexplained iron, vit b12 or folate deficiency IBS in adults Dermatitis herpetiformis- vesicular itchy rash that occurs due to IgA deposition along the dermal papillae
Investigations to diagnose coeliacs
If possible patients should be on a gluten containing diet for 6 weeks prior to investigations Screening: 1st line: serological test for IgA antibodies against tTG (anti-tTG) - total IgA must also be measured as may get false -ve in IgA deficient patients 2nd line: endomysial antibodies (IgA) if anti-tTG is weakly positive Diagnostic: gold standard Duodenal biopsy for all patients with positive serology Findings: crypt hyperplasia, villous atrophy, intraepithelial lymphocyte infiltration
Treatment for coeliacs
Gluten-free diet Avoid : wheat, rye, barley sometimes oats -Rice, potatoes and corn are gluten free -Replace vitamins and mineral’s deficiency if needed -Offer pneumococcal vaccination with boosters every 5 years
Complications of coeliacs
Dermatitis herpetiformis Malignancy Increased risk of osteoporosis Calcium and vit D deficiency
Differental diagnosis with coeliacs
Sprue or tropical sprue (associated with tropical travel) = malabsorption syndrome -Similar biopsy to coeliacs- crypt hyperplasia and villous atrophy -Treatment = often antibiotics eg tetracycline
What is IBS?
Chronic, relapsing and often lifelong disorder that affects lower GI tract - no discernible structure or biochemical cause => considered ‘functional’
Cause of IBS
Multi factorial Genetics + environmental + psychological (stress, anxiety) + dietary Exact mechanism unknown
Categorisation of IBS
IBS-C —> mostly constipation IBS-D —> mostly diarrhoea IBS-M —> mostly mixed; alternating C/D
Risk factors of IBS
Young adults Females Family history Dietary factors Psychosocial cavities Drugs
Symptoms of IBS
Abdominal pain and bloating relieved from defecation -Altered stool form/frequency
Diagnosis to exclude before diagnosing IBS
Coeliacs (serology) IBD (check fecal calprotectin) Infections (ESR/CRP/Blood cultures)
Investigations to diagnose IBS
IBS is a diagnosis of exclusion so no specific investigation to confirm diagnosis May use following to exclude other conditions: - FBC - ESR/CRP - coeliac serology
Treatment for IBS
1st line: conservative patient education, dietary advice and patient reassurance, address any cormorbid stress or anxiety For IBS-C consider more fibre and for IBS-D consider probiotics 2nd line: IBS-C —> laxatives (senna/Fybogel) IBS-D —> antimotility drug (loperamide) 3rd line: For severe abdominal pain consider low-dose trycyclic antidepressant (TCA eg amitriptyline) - consider CBT for psychological support - refer to gastroenterologist
Complications of IBS
Mood disorders: more severe and frequent depression and anxiety Poor quality of life: miss three times as many days off work
What is GORD
Gastric-oesophageal reflux disease = reflux of gastric contents into oesophagus due to decreased pressure across lower oesophageal sphincter
Causes of GORD
- raised intragastric pressure= obesity + pregnancy - hiatal hernia (mostly with LOS sliding up through diaphragm) - Drugs anti-muscarinics, CCBs - Scleroderma (LOS = scarred)
Symptoms of GORD
“Heartburn” -Retrosternal burning chest pain that is exacerbated by lying flat -Sour/bitter taste of acid in the back of the mouth -dysphagia -nausea -chronic cough
Investigations to diagnose GORD
If no red flags go a traight to treatment (PPI) Red flags (dysphagia, haematemeis, weight loss) - endoscopy —> oesphagitis or Barrett’s - oesophagal manometry —> measure functionality of LOS and gastric acid pH
Treatment for GORD
-Conservative lifestyle changes (smaller meals, 3+hrs before bed, avoidance of trigger foods) -medication review: consider reducing or stoppping medications that are causing symptoms eg CCB -PPI offer full dose for 1-2 months If symptoms persists use PPI at lowest dose possible as maintenance If symptoms still persist or CI then use H2RA
Last resort for GORD treatment?
Surgical treatment- laparoscopic fundoplication = mobilisation of funded of stomach which is then wrapped around the lower oesophageal sphincter to tighten it
Complications of GORD
Barrett’s oesophagus-oesophageal stricture - fibrous scarring and therefore narrowing of oesophageal lumen -dental problems
Barrett’s oesophagus
-10-15% develop Barrett’s -Always involves hiatal hernia -Metaplasia (SSNKE —>simple columnar) -Increased risk of adenocarcinoma -Diagnose with a Biopsy Pathway for oesphagus changes: Normal—> metaplasia (Barrett’s) —> dysplasia (adenocarcinoma)
What is Mallory Weiss Tear?
Linear lower oesophageal mucosal tear due to sudden increase in intra-abdominal pressure at the border of the gastro-oesophageal junction Limited to mucosa and submucosa
Typical presentation of Mallory-Weiss Tear?
Presents typically as a young male with acute history of retching and vomiting after a night out eventually causing haematemesis Causes a laceration resulting in an upper GI bleed that is usually self-limiting.
Differential diagnosis for MWT?
Boerhaave’s syndrome -spontaneous perforation of the oesophagus -usually due to vomiting -ruptures all the layers of the oesophageal wall (transmural) -unlike MWT it’s a surgical emergency
Risk factors of a Mallory Weiss Tear?
-Any condition that predisposes to retching or vomiting: gastroenteritis, bulimia, hyperemesis - Alcoholism - chronic cough - hiatus hernia - GORD - Male - age 40-60
What if a patient has haematemesis and pulmonary hypertension?
oesophageal varices rupture
Symptoms of MWT
Background of alcohol excess presenting with episodes of violent retching or vomiting - Haematemesis (Usually small to moderate volume of bright red blood which is self limiting) - hypotensive in severe cases but unlikely
Investigations to diagnose MWT
Upper GI endoscopy (gold standard) required for all patients depending on the Glasgow Blatchford score - usuallay shows a single longitudinal tear (can be multiple) in the mucosa at the gastro-oesophageal junction
Scoring system for upper GI bleeds
Glasgow Blatchford Score Score >0 means patient require admission for inpatient endoscopy Score 0 means patient can be discharged Most accurate in identifying risk patients in need of transfusion
What is the Rockall score?
Calculated after endoscopy to identify patients at risk of adverse outcomes after treatment for an upper GI bleed
Treatment for MWT
Most spontaneously heal within 24h!
What type of peptic ulcer is more common?
Gastric>Duodenal Gastric is 2/3x more common
What are peptic ulcer diseases?
Punched out round holes in either stomach or stomach or duodenum
Where do gastric ulcers occur
Mostly at a lesser curve
Causes of gastric ulcers
-H.pylori (causes of 75% of gastric ulcers) -NSAIDs -Zolinger Ellison syndrome: - pancreatic tumour - gastric acid hypersecretion - widespread peptic ulcers
Symptoms of gastric ulcers
Epigastric pain - worse on eating - better between meals + with antacids * typically weight loss
Investigations to diagnose gastric ulcers
If no red flags (55+, haematemesis/melaena, anaemia, dysphasia) - non invasive tests: c-urea breath test Stool antigen test If red flags - urgent endoscopy + biopsy
Complications of peptic ulcer disease
-Bleeding -Perforation: life threatening as ulcer penetrates the duodenum or stomach into the peritoneal cavity; requires surgical intervention -Gastric outlet obstruction: caused by obstruction at pylorus due to an ulcer and subsequently scarring. Presents with vomiting and nausea after food
Location of Duodenal ulcers?
mostly at D1 and sometimes D2 -the gastroduodenal artery is located at the posteromedial aspect of D2 so deeply penetrating ulcers in this region can result in a torrential upper GI bleed
Causes of duodenal ulcers
H. Pylori (causes 95% of duodenal ulcers) NSAIDS ZE Syndrome
Symptoms of duodenal ulcers
Epigastric pain - worse between meals - better with food * typically weight gain
Investigations to diagnose duodenal ulcers
If no red flags: - non-invasive testing 1. Urea breath test 2. Stool antigen test If red flags: Urgent endoscopy + biopsy (Will see Brunner’s gland hypertrophy- more mucous production)
What do you have to make sure of before testing for H.pylori?
If testing for h.pylori, patient must be off PPI for 2 weeks+ (all ulcers) - otherwise you can get a false -ve
Treatment for both gastric and peptic ulcers?
Stop NSAIDs 1) H.pylori +ve -> triple therapy CAP Clarythromycin Amoxicillin PPI (omeprazole) (If they have a penicillin allergy replace amoxicillin with metronidazole) 2) H.Pylori -ve give PPI at initial high dose for a month until ulcer healed Ensure all patients who have a proven ulcer have a repeat endoscopy 6-8 weeks later to confirm healing as well as h.pylori retesting
What is gastritis?
Mucosal inflammation and injury
Causes of gastritis
Autoimmune (related to pernicious anaemia + anti intrinsic factor antibodies) H. Pylori NSAIDs (causes gastropathy- injury without inflammation) Mucosal ischaemia Campylobacter (GBS) + viral (CMV)
Symptoms of gastritis?
Epigastric pain with diarrhoea Nausea and vomiting Indigestion
What is PUD a complication of?
Gastritis
Investigations to diagnose gastritis?
If H.pylori suspected: - stool antigen test/ urea breath test Gold standard= endoscopy + biopsy
Treatment for gastritis?
H. Pylori = triple therapy CAP Clarythromycin Amoxicillin PPI
Pathophysiology of H.Pylori?
Commences in stomach- not usually diarrhoea causing - Decreased virulence and is typically opportunistic 1) decreases stomatostatin 2) decreases luminal HCO3 3) secretes urease 4) inscreases gastrin release Urea —urease—> CO2 + NH3 NH3 + N+ —reversible—> NH4+ (toxic)
What is autoimmune gastritis?
Affects funds portion of the stomach Especially causes atrophy of parietal cells
What is appendicitis?
Acute inflamed appendix, usually due to luminal obstruction SURGICAL EMERGENCY
Epidemiology and risk factors of appendicitis?
10-20yrs old Male Frequent antibiotic use Smoking
Causes of appendicitis?
Blockages: - Faecolith (hard mass of stool) - foreign body - lymphoid hyperplasia of Peyer’s patches (teens) - fibrous strictures Blockage is typically infected with e.coli and as pressure inside appendix increases, so does rupture risk
Mechanisms of pain in appendicitis?
Peri umbilical pain: inflammation of appendix and visceral peritoneum irritates autonomic nerves of the embrylogical midgut —> referred pain to the umbilical region Right iliac fossa: due to localised inflammation of the parietal peritoneum
Classic triad presentation of appendicitis?
1) central abdominal pain that migrates to right iliac fossa 2) low-grade pyrexia 3) anorexia 50% of patients present with this characteristic history
Symptoms of appendicitis?
1) periumbilical pain that migrated to the right iliac fossa (McBurney’s point) (rebound or percussion tenderness) 2) low grade fever >38°C 3) reduced appetite and anorexia 4) nausea and vomiting 1) McBurney’s point 2) umbilicus 3) right ASIS
Signs of appendicitis?
1) Rosving’s sign (pressing on left Illiac fossa causes right illiac fossa pain to get worse) 2) Psoas sign (pain worsened by lying on left side and extending the right leg) 3) Obturator sign (pain worsened by flexing and internally rotating the hip)
Complications of appendicitis?
Perforation (15-20%) - appendiceal rupture Appendiceal mass Periappendical abscess