Gastrointestinal (2) Flashcards
Define coeliac disease
Systemic autoimmune inflammatory disease triggered by dietary gluten peptides found in wheat, rye, barley, and related grains.
Gluten intolerance which leads to villous atrophy and crypt hyperplasia cuasing chronic intestinal malabsorption.
Explain the aetiology of coeliac disease
Due to sensitivity to the GLIADIN component of gluten. Gliadins are resistant to proteases and persist in SI where they are deamidated by tTG. Exposure to gliadin triggers an immunological reaction in the small intestine leading to mucosal damage and loss of villi.
What are the risk factors of coeliac disease?
Family history of coeliac disease IgA deficiency T1DM Autoimmune thyroid disease Genetic susceptibility associated with HLA-B8, HLA-DR3 and HLA-DQW2 haplotype.
Describe the epidemiology of coeliac disease
Common in Irish
Prevalence around 1%
Women slightly more likely
Can be diagnosed at any age
1st peak period of presentation = infancy soon after the initial exposures to gluten
2nd peak period of presentation = fourth and fifth decades
What are the presenting symptoms of coeliac disease?
Diarrhoea Bloating Abdominal pain/discomfort/distension Steatorrhoea Fatigue Weight loss Failure to thrive Amenorrhoea
What are the signs on examination of coeliac disease?
Signs of anaemia: pallor
Signs of malnutrition: Short stature, Abdominal distension, Wasted buttocks in children
Signs of vitamin/mineral deficiencies: osteomalacia, easy bruising, aphthous ulcers
Dermatitis herpetiformis: Intense, itchy blisters
on elbows, knees or buttocks
What are the appropriate investigations for coeliac disease?
Blood: FBC (low Hb, iron and folate, microcytic) Albumin - low Calcium - low Phosphate - high
Serology:
IgG anti-gliadin antibodies, IgA and IgG anti-endomysial tranglutaminase antibodies can be diagnostic (IgA and IgG-tTG) IgA may give false negative
Stool: culture to exclude infection, faecal fat tests for steatorrhoea
D-xylose test: reduced urinary excretion after oral xylose indicates small bowel malabsorption
Endoscopy: allows direct visualisation of villous atrophy
in the small intestine (mucosa appears flat and smooth)
Biopsy: villous atrophy and crypt hyperplasia in the duodenum. Epithelium adopts a cuboidal appearance, inflammatory infiltrate of lymphocytes and plasma cells in the lamina propri.
What is the management for coeliac disease?
Avoid gluten
Vitamin and mineral (calcium, vit D, iron) supplements
Oral corticosteroids if avoidance of gluten does not subside disease
What are the possible complications of coeliac disease?
Osteoporosis/osteopenia
Dermatitis herpetiformis
Malignancy - lymphoma, small bowel and oesophageal cancer
Idiopathic recurrent acute/chronic pancreatitis
Pneumococcal infection
Iron, folate, B12 deficiency
Ulcerative jejunoileitis
What is the prognosis of coeliac disease?
Most patients have complete and lasting resolution of symptoms on a gluten-free diet alone. Symptoms usually resolve within a few weeks.
For those with persistent symptoms, most of these will be attributed to ongoing gluten exposure, lactose intolerance, and IBS.
Less than 1% can be expected to develop refractory coeliac disease.
Define colorectal carcinoma
Malignant adenocarcinoma of the large bowel
Distribution:
60% - rectum and sigmoid
30% - descending colon
10% - rest of colon
What are the risk factors for colorectal carcinoma?
Western diet (e.g. red meat, alcohol) Colorectal polyps Previous colorectal cancer Family history IBD Increasing age Familial adenomatous polyposis (FAP) – APC mutation, autosomal dominant Hereditary non-polyposis colorectal cancer (HNPCC or Lynch syndrome) – microsatellite instability, autosomal dominant Obesity
Summarise the epidemiology of colorectal carcinoma?
Third most common cancer in the Western world.
Highest incidence in Europe, North America and Australasia
Lowest incidence in Africa and Asia
Rare before 40 years old - average age of diagnosis is 60-65
What are the presenting symptoms of colorectal carcinoma?
Left-Sided Colon and Rectum:
Change in bowel habit
Rectal bleeding (blood or mucus mixed with the stools)
Tenesmus (due to a space-occupying tumour in the rectum)
Right-Sided Colon:
Presents later Anaemia symptoms (lethargy) Weight loss Non-specific malaise Lower abdominal pain (rare) Blood covering stool or streaked
20% of tumours will present as an EMERGENCY with pain and distension due to:
Large bowel obstruction
Haemorrhage or peritonitis due to perforation
What are the signs on examination of colorectal carcinoma?
Anaemia
Abdominal mass
Low-lying rectal tumours may be palpable on DRE
If metastatic: Hepatomegaly, Ascites (shifting dullness)
What are the appropriate investigations for colorectal carcinoma?
Bloods:
FBC - anaemia
LFTs
Tumour markers - CEA
DRE
Stools:
Faecal Occult Blood Test - screening test
Endoscopy: Sigmoidoscopy or Colonoscopy and biopsy
Double-Contrast Barium Enema
Contrast CT - For staging (Duke’s staging)
Define Crohn’s disease
A chronic relapsing and remitting granulomatous systemic disease involving transmural inflammation of any part of the gastrointestinal tract.
Describe some of the difference between Crohn’s Disease and Ulcerative Colitis
Depth - Crohn’s is transmural inflammation whereas UC only affects the mucosa
Location - CD can affect anywhere in the GI tract from mouth to anus but is usually terminal ileum and ascending colon, UC affects rectum extending proximally
CD is often patchy with skip lesions but UC is continuous inflammation
CD has pathognomonic granulomas (swellings,
macrophages, giant cells), thickened bowel wall with strictures, fistulae and abscesses, aphthous ulcers
UC has red, inflamed, friable mucosa, crypt ulcers and pseudopolyps
What are the risk factors of Crohn’s Disease?
Unknown aetiology but relation between genetic and environmental factors
Genetic factors: Family history CARD15 HLA-B27 Increased serum p-ANCA
Environmental factors: Smoking OCP NSAIDs High sugar and fat intake Chronic stress and depression Intestinal dysbiosis Infectious agents Dietary deficiencies Age 15-40 or 60-80
Describe the epidemiology of Crohn’s Disease
Peak age of onset is 15-40 years and a smaller peak at 60-80 years. Equally prevalent among men and women. More common in white people. Higher prevalence among smokers. UK prevalence: 50-80/100,000
What are the presenting symptoms of Crohn’s Disease?
Crampy abdominal pain (due to inflammation, fibrosis or bowel obstruction)
Diarrhoea (may be bloody or steatorrhoea)
Fever, malaise, weight loss
Symptoms of complications
Sometimes right iliac fossa pain due to inflammation of terminal ileum
What are the signs on examination of Crohn’s Disease?
Weight loss
Clubbing
Signs of anaemia
Abdominal tenderness
Aphthous ulcers in mouth
Perianal lesions - skin tags, fistulae and abscesses
Uveitis, erythema nodosum, pyoderma gangrenosum
What are the appropriate investigations for Crohn’s Disease?
Bloods: FBC - Low Hb, high WCC and platelets Raised ESR/CRP Low albumin Deranged LFTs (associated liver disease) Iron studies - may show iron deficiency Serum B12 and folate - may be low due to malabsorption
Stool:
MC&S – exclude infectious colitis
Faecal calprotectin – indicates migration of neutrophils to intestinal mucosa i.e. inflammation; distinguishes IBD from IBS and assesses disease severity
AXR – dilated bowel loops indicates ileus, exclude toxic megacolon
Erect CXR - abdominal perforation
OGD or colonoscopy Monitor disease severity/progression Cobblestone mucosa Fistulae/abscesses Granulomas
Small bowel barium follow-through:
Deep ulceration
Fibrosis/strictures (string sign of Kantor: part of intestine looks like a piece of string, showing incomplete filling of intestinal lumen)
Cobblestone mucosa
CT/MRI - skip lesions, bowel wall thickening, surrounding inflammation, abscess, fistulae
What is the management for Crohn’s Disease?
Acute Exacerbation:
Fluid resuscitation
IV/oral corticosteroids
5-ASA analogues (e.g. mesalazine and olsalazine)
Analgesia
Parenteral nutrition may be necessary
Monitor markers of disease activity e.g. fluid balance, ESR, CRP, platelets, Hb
Long-Term:
Steroids - for acute exacerbations
5-ASA analogues - decreases the frequency of relapses (useful for mild to moderate disease)
Immunosuppression: using steroid-sparing agents (e.g. azathioprine, 6-mercaptopurine, methotrexate) reduces the frequency of relapses
Anti-TNF agents: (e.g. infliximab and adalimumab) - very effective at inducing and maintaining remission. Usually reserved for refractory Crohn’s.
General Advice:
Stop smoking
Dietician referral (low fibre diet necessary if there are stricture present)
Surgery indicated if:
Medical treatment fails
Failure to thrive in children in the presence of complications
Involves resection of affected bowel and stoma formation
What are the possible complications of Crohn’s Disease?
Anaemia
GI: Abscess Haemorrhage Obstruction Strictures Perforation Fistulae (between bowel, bladder, vagina) Perianal fistulae and abscesses GI cancer Malabsorption Toxic megacolon
Extraintestinal Features: Uveitis Episcleritis Gallstones Kidney stones Arthropathy Sacroiliitis Ankylosing spondylitis Erythema nodosum Pyoderma gangrenosum Amyloidosis Primary sclerosing cholangitis
What is the prognosis of Crohn’s Disease?
CD is a chronic disease with variable frequency of relapses and multiple possible complications.
Intermittent exacerbations followed by periods of remission, with 10% to 20% of patients experiencing a prolonged remission after the initial presentation.
2/3 of CD patients will require surgery
CD has lower life expectancy
Define Diverticular Disease
Diverticular disease = diverticulosis associated with complications.
Diverticulosis = the presence of diverticulae outpouchings (herniation of the mucosa and submucosa through the muscular layer of the large bowel wall).
Diverticulitis = acute inflammation of a diverticulum or diverticula
What is the aetiology/risk factors of diverticular disease?
Low-fibre diet leads to loss of stool bulk. Leads to generation of high colonic intraluminal pressures to propel the stool out. Leads to the herniation of the mucosa and submucosa through the muscularis
Inspissated food or faecal matter can cause diverticular obstruction -> bacterial overgrowth, toxin production and mucosal injury -> diverticulitis
Most commonly found in sigmoid and descending colon. NOT in rectum.
Risk factors: Low dietary fibre (Western diet) Age >50 y Decreased physical activity Obesity Increased red meat consumption Tobacco smoking Excessive alcohol and caffeine intake Steroids NSAIDs
Summarise the epidemiology of diverticular disease
Prevalence is difficult to determine because most patients are asymptomatic but VERY COMMON.
Prevalence increases with age - affects 50% to 66% of over 80 year olds.
Right-sided diverticular disease is more common in Asia.
No overall sex difference in prevalence of diverticular disease.
What are the presenting symptoms of Diverticular Disease?
Often asymptomatic Left lower quadrant pain Diarrhoea PR bleeding Bloating Constipation
If diverticulitis - LIF and lower abdo pain and fevero
If diverticular fistulation - causing pneumaturia (see bubbles in urine), faecaluria and recurrent UTI
What are the signs on physical examination of Diverticular Disease?
Guarding and tenderness in LLQ
Pelvic tenderness on DRE
Signs of generalised peritonitis if a diverticulum has perforated
What are the appropriate investigations for Diverticular Disease?
Bloods:
FBC - raised WCC if acute diverticulitis, raised CRP
Abdo CT - thickening of bowel wall, mass, abscess, streaky mesenteric fat, gas in the bladder in cases of fistula.
Abdo USS - if CT unavailable
Abdo X-ray - pneumoperitoneum, ileus, soft tissue densities, free air in bowel perforation if acute diverticulitis
CXR - if suspect perforation
Barium Contrast enema - saw-tooth appearance of lumen. Used to confirm acute diverticulitis diagnosis following resolving of symptoms - do not use in acute setting as risk of perforation.
Colonoscopy or sigmoidoscopy - if unclear or supsect bowel cancer
Angiogram if profuse bleeding
What is the management plan for Diverticular Disease?
Asymptomatic:
Soluble high-fibre diet (20-30 g/day) and increase fluids
Probiotics and anti-inflammatories??
GI Bleed:
IV rehydration and antibiotics
Blood transfusion if necessary
Angiography and embolisation or surgery if severe
Diverticulitis:
IV antibiotics
IV fluid rehydration
Bowel rest
Abscesses may be drained by radiologically sited drains
Surgery:
Necessary in patients with recurrent attacks or complications (e.g. perforation and peritonitis)
Open surgery:
Hartmann’s procedure (proctosigmoidectomy leaving a stoma)
One-stage resection and anastomosis (risk of leak) with or without defunctioning stoma
Laparoscopic drainage, peritoneal lavage and drain placement can be effectively
What are the possible complications of Diverticular Disease?
Diverticulitis Pericolic abscess Perforation Faecal peritonitis Colonic obstruction Fistulae - Bladder: causes pneumaturia, faecaluria, recurrent UTI - Small intestine - Vagina Haemorrhage Strictures
What is the prognosis of Diverticular Disease?
Most patients with uncomplicated diverticulitis recover following medical treatment and do not require surgical intervention.
Diverticular disease recurs in one third of patients following response to medical treatment, mostly within 5 years.
Following surgical treatment, approximately one fourth of all patients continue to remain symptomatic.
10-25% have one or more episode of diverticulitis
Define Irritable Bowel Syndrome
Chronic condition characterised by abdominal pain and bowel dysfunction with no underlying structural abnormalities – diagnosis of exclusion
What is the aetiology/risk factors of IBS?
No specific aetiological cause (mucosa is normal)
Disorder of GI motility with a potential inflammatory/immune basis often triggered by stress
Risk factors: Female Age <50 years GI infection Previous physical or sexual abuse Stress
What is the epidemiology of IBS?
Affects 10-15% of adults
The prevalence is higher in women than men
Rare for onset of symptoms after 50 years
What are the presenting symptoms of IBS?
Abdominal discomfort
Altered bowel habits associated with pain
Bloating
Passage of mucus with stool
Cramping pain relieved following defecation
What are the signs on physical examination of IBS?
Nil signs of note - a normal abdominal exam
