Gastroenterology (Small and large bowel) Flashcards
coeliac disease
autoimnmune condition that primarily affects the small intestine
pathophysiology
- reaction to gluten causes bluting of villi, reducing absorption of nutrients from the small intestine
coaliac risk factors
- Family history
- Immunoglobulin A (IgA) deficiency
- Type 1 diabetes
- Autoimmune liver disease
- Autoimmune thyroid disease
- Human leukocyte antigen (HLA)-DQ2 and HLA-DQ8
presentation of coeliac
Persistent and unexplained gastrointestinal symptoms such as:
- Abdominal pain
- Bloating
- Diarrhoea
- Constipation
- Steatorrhoea
Features of malabsorption:
- Weight loss and failure to thrive
- Anaemia – may be iron-deficiency anaemia or anaemia secondary to B12/folate deficiency
- Metabolic bone disorders (e.g. osteomalacia, osteopenia, or osteoporosis) and fragility fractures due to malabsorption of calcium and vitamin D
Mouth ulcers that may be persistent or severe
coeliac associated conditions
- Unexplained depression or anxiety
- Unexplained peripheral neuropathy
- Unexplained ataxia
- Unexplained subfertility or recurrent miscarriage
- Unexplained persistently slightly elevated AST/ALT on liver function testing
- Unexplained hyposplenism
- Dermatitis herpetiformis – a rash associated with a transglutaminase enzyme in the skin
when to screen for coeliac
The following patients should be offered screening for coeliac disease:
- Persistent unexplained gastrointestinal symptoms
- Unexplained weight loss, faltering growth, or failure to thrive
- Severe or persistent mouth ulcers
- Unexplained iron-deficiency, B12, or folate deficiency
Patients with associated conditions:
- Type 1 diabetes mellitus (T1DM) – should be done at the time T1DM is diagnosed
- Autoimmune thyroid disease – at the time it is diagnosed
- Irritable bowel syndrome
- Dermatitis herpetiformis
- 1st-degree relatives with coeliac disease
Screening should be considered if any of the following are present:
* Metabolic bone disorders
* Unexplained peripheral neuropathy or ataxia
* Unexplained complications in pregnancy, including recurrent miscarriage and subfertility
* Unexplained persistently elevated liver AST/ALT
* Down’s syndrome
* Turner syndrome
* Dental enamel defects
screening for coeliac
different to diagnosis
MAKE SURE PATIENT CONTINUES TO EAT GLUTEN FOR A MIUM OF 6 WEEKS BEFORE TESTING
1st-line: serum IgA tissue transglutaminase antibody (tTGA) + total IgA
- Total IgA is measured because, in some individuals with an IgA deficiency, this may return a negative result
2nd-line: IgA endomysial antibody (EMA) if IgA tTGA is unavailable
- Consider re-testing if a person presents with new symptoms of coeliac disease, despite previous serology
why is total IgA measured
- Total IgA is measured because, in some individuals with an IgA deficiency, this may return a negative result
diagnosis of coeliac
gold standard: biopsy of the duodenum and jejunum
- villous atrophy
- crypt hyperplasia
- intrapeithelial lymphocytosis
- infiltration of the lamina propria and lymphocytes
management of coeliac disease
- 1st-line: lifelong gluten-free diet
- Monitoring with IgA tTGA or IgA EMA may be considered to assess compliance
- Offer annual influenza vaccine and 5-yearly pneumococcal vaccine:
why pneumoccocal vaccine for
Around 1/3 of patients with coeliac disease have hyposplenism, predisposing them to pneumococcal infection. This is thought to be due to functional hyposplenism and splenic atrophy
complications of coeliac
- anaemia - B12 deficiency
- osteoporosis
- hyposplenism
- lymphomas
- subfertility
irritable bowel syndrome is a disorder of the
gut-brain interaction
risk factors for IBS
- Diet: 90% of patients report that certain foods can trigger symptoms e.g. items are spicy foods, fatty foods, alcohol, and caffeine
- GI tract infection
- Family history
- Antibiotic use
- GI tract inflammation
- Psychological comorbidities including stress, anxiety, or depression
*
presentation of IBS
6- month history of ABC symptoms
Abdominal pain/discomfort:
- The pain generally varies, which can help differentiate IBS from malignancy, where the site of pain is usually fixed
Bloating
Changes in bowel habit
IBS extraintestinal features
- Lethargy
- Headache
- Nausea
- Back pain
- Gynaecological and bladder symptoms
how to differentiate between IBS, IBD, cancer and coeliac
IBS: Clinical diagnosis in primary care
IBS can be diagnosed if abdominal pain/discomfort has been ongoing for 6 months and the following apply:
1) Is relieved by defecation or is associated with changes in bowel frequency (increased/decreased) or stool form (e.g. loose, watery, hard, or lumpy)
2) At least 2 of the following are present:
- Altered stool passage – such as straining, urgency, or feeling of incomplete stool passage
- Abdominal bloating, distention, tenderness, or hardness
- Symptoms are worse when eating
- Passage of mucus
3) Alternative conditions with similar symptoms have been excluded, including red flags and serious conditions
management of IBS
Management depends on the predominant symptom:
1) For constipation: laxatives are first-line
- Any option is appropriate except lactulose as it can increase gas production
- Linaclotide can be considered if first-line options are insufficient
2) For diarrhoea: loperamide is first-line
3) For abdominal pain: antispasmodic agents are first-line
- Options include direct-acting smooth muscle relaxants: mebeverine hydrochloride, alverine citrate, and peppermint oil
- These are less likely to cause adverse effects compared with antimuscarinic drugs such as hyoscine butylbromide
Other options
* Tricyclic antidepressants are considered 2nd-line
* Cognitive behavioural therapy may be necessary
inflammatory bowel disease
Umbrella term for: Crohsna nd ulcertaive colitis
Crohns vs Ulcerative colitis
Features suggesting Crohn’s disease are:
- Diarrhoea does not usually contain as much blood as UC
- Fever is often present
- Tenesmus (the feeling of needing to pass stools even though the bowel is empty) is less common
- Weight loss is more common
- Fistulae is more common
- CD can affect any part of the gastrointestinal (GI) tract from mouth to anus (e.g. mouth ulcers)
Features suggesting ulcerative colitis are:
- Diarrhoea often contains mucus and blood
- Fever is sometimes present, usually if a UC flare is severe
- Tenesmus is more common
- Weight loss is less common than in CD
- Fistulae is less common than in CD
- UC only affects the colon and rectum
Endoscopic features suggesting CD
- Skip lesions (patchy inflammation) anywhere from the mouth to the anus
- Perianal disease is more common than in UC
- Inflammation is in all layers (transmural) of GI tissue
- Histology shows Goblet cells and granulomas
Endoscopic features suggesting UC
- Inflammation is continuous anywhere from the ileocaecal valve to the rectum
- Perianal disease is less common than in CD
- Inflammation is more shallow, usually affecting the superficial mucosa
- Histology shows crypt abscesses
investigations for IBD
Full blood count:
- May show anaemia which can be due to chronic inflammation, blood loss, or iron/B12/folate malabsorption
- Increased white cells suggest acute or chronic inflammation
- Increased platelets suggest active inflammation
Iron studies:
- To identify iron deficiency
Haematinics:
- To assess serum B12 and folate:
C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR):
- Elevated in inflammation
Stool testing:
- To rule out an infection such as Clostridioides difficile
Faecal calprotectin:
- A non-specific marker released from neutrophils in gastrointestinal tract inflammation
- Can help with differentiating IBD from irritable bowel syndrome (IBS)
Colonoscopy with biopsies:
GOLD STANDARD!!! The diagnostic test. CD and UC have differing features.
complications of IBD
Anaemia:
- Occurs due to malabsorption and blood loss
Intestinal obstruction – more common in CD
- Occurs due to bowel wall thickening during acute inflammation
Malabsorption, malnutrition, and dehydration – seen in CD, not UC:
- Inflammation of the small bowel can damage the intestinal mucosa, which can lead to reduced absorption
Colorectal cancer
Extra-intestinal manifestations of IBD
Ankylosing spondylitis:
- Presents as lower back pain which can radiate into the buttocks
Polyarthritis:
- Affecting ≥5 joints, such as the small joints of the hands
- Usually symmetrical and can leave permanent damage
Pyoderma gangrenosum:
- Most commonly seen on the shins and at sites of previous trauma
Psoriasis
Anterior uveitis:
- More common in UC
- Usually bilateral and insidious in onset
- Presents as a painful red eye with blurred vision, photophobia, and headaches
Primary sclerosing cholangitis:
- More common in UC
Gallstones:
- More common in CD:
- Occurs due to malabsorption of bile acids due to ileitis
- Since UC does not affect the ileum, this is less common
extra-intestinal manifestations related to IBD disease activity
**Pauci-articular arthritis **– the most common extra-intestinal manifestation of IBD
- Arthritis affecting <5 large joints (e.g. shoulders, elbows, wrists, hips, or knees)
- Usually asymmetric, lasts for weeks, and does not usually cause permanent damage
- There may be associated enthesitis (inflammation where a tendon attaches to a bone), tenosynovitis (inflammation of a tendon or its sheath), or dactylitis (inflammation of an entire finger/toe)
Erythema nodosum:
- Usually on the anterior tibia or extensor surfaces of the legs
Mouth ulcers:
- More common in CD
Episcleritis:
- More common in CD
- Red eye with injected sclera and conjunctiva
- Classically painless, but can have some discomfort, itching, or burning
Metabolic bone disease(e.g. osteoporosis, osteopenia, osteomalacia):
- May be due to malabsorption, inflammation, or corticosteroid treatment
Crohns key features
Crohns
- mouth to andus
- patchy inflammation - skip lesions
- transmural (fistulas, adhesions and strictures)
RF for crohns
- Family history
- Smoking
- NSAID use
presentation of Crohns
Non-specific features:
- Fatigue
- Weight loss
- Malaise
- Fever
Chronic and unexplained diarrhoea (for more than 4-6 weeks):
- If the colon is affected (colitis), then diarrhoea may be bloody
Abdominal pain:
- May be due to active inflammation adhesions, fistulas, strictures, or obstruction
crohns exam findings
- Finger clubbing
- Mouth ulcers
- Pallor: Due to anaemia
- Signs of malnutrition and malabsorption: In children, there may be a failure to thrive or delayed puberty
- Abdominal tenderness or a mass: Often in the lower right quadrant suggesting terminal ileal inflammation
Signs of perianal disease:
- Perianal pain or tenderness
- Skin tags
- Fissures
- Fistulas
- Abscesses
Signs of extraintestinal manifestations
crohns: inducing remission
1st-line:
- Glucocorticoids (e.g. oral prednisolone or IV hydrocortisone) + taper
- Budesonide may be used if glucocorticoids are contraindicated/not tolerated
- 5-aminosalicylate (5-ASA) drugs (e.g. mesalazine) may be considered as an alternative to glucocorticoids and budesonide, but are less effective
2nd-line:
- add-on azathioprine or mercaptopurine:
- If azathioprine and mercaptopurine are inappropriate, methotrexate may be used instead
- Do not offer azathioprine, mercaptopurine, or methotrexate as monotherapy
- If the above measures fail or are not tolerated, infliximab or adalimumab may be considered
maintaining remission in crohns
- Patients should be advised to stop smoking as it can worsen CD
- 1st-line: azathioprine or mercaptopurine
- TPMT activity should be checked first
- 2nd-line: methotrexate
patient advice for crohns
- dont smoke
- no NSAIDS or COCP
ulcerative colitis
a type of inflammatory bowel disease (IBD) that characteristically starts at the rectum and extends proximally, affecting variable lengths of the colon.
* It does not extend past the ileocaecal valve.
* Its pathophysiology is not fully understood, however, genetic and environmental factors are implicated.
features of UC
- continuous
- superficial
risk factors for UC
Family history
HLA-B27
Infection
NSAID use
presentation of UC
The main feature of UC is bloody diarrhoea, generally persisting for more than 6 weeks.
- Rectal bleeding
- Faecal urgency
- Faecal incontinence
- Tenesmus
- Abdominal pain: lower left quadrant
Non-specific symptoms:
- Fatigue
- Malaise
- Anorexia
Fever may be seen – suggesting a more serious disease
UC classification
NICE has categorised UC into mild, moderate, and severe. This stratification guides management:
Mild:
- <4 stools per day
- Small amounts of blood
Moderate:
- 4-6 stools per day
- Varying amounts of blood
- No features of systemic upset (e.g. fever >37.8°C, raised CRP/ESR >30 mm/hr, anaemia, tachycardia >90 bpm)
Severe:
- > > 6 stools per day
- Visible blood
- Features of systemic upset
UC: inducing remission
In mild-moderate UC:
Proctitis (UC affecting the rectum):
- 1st-line: topical (rectal) aminosalicylate (e.g. mesalazine and sulfasalazine)
- If no remission within 4 weeks: add oral aminosalicylate
- If remission is still not attained: a time-limited course (4-8 weeks) of topical or oral corticosteroid
Proctosigmoiditis and left-sided UC:
- 1st-line: topical aminosalicylate
- If no remission within 4 weeks: add high-dose oral aminosalicylate or switch to high-dose oral aminosalicylate + topical corticosteroid
- If remission is still not attained: stop topical treatment and give oral aminosalicylate and oral corticosteroid
Extensive disease:
- 1st-line: topical aminosalicylate + high-dose oral aminosalicylate
- If no remission within 4 weeks: stop topical treatment and give oral aminosalicylate and oral corticosteroid
In severe UC:
Patients with severe UC should be admitted to hospital
- 1st-line: IV corticosteroids
- If contraindicated, IV ciclosporin may be used
- If complications such as toxic megacolon, perforation, haemorrhage, or shock occur, surgery is indicated
UC Maintaining remission
Maintaining remission depends on the site and severity of UC:
Proctitis and proctosigmoiditis:
- Topical aminosalicylate daily/intermittent or
- Topical aminosalicylate daily/intermittent + oral aminosalicylate or
- Oral aminosalicylate only
Left-sided and extensive UC:
- Low maintenance dose of oral aminosalicylate
After a severe relapse or ≥2 flare-ups in the last year:
- Oral azathioprine or oral mercaptopurine
- Check thiopurine methyltransferase (TPMT) activity before giving these
UC advice
- Despite smoking being associated with a decreased likelihood of a UC flare, the research is mixed. The risks associated with smoking such as COPD, heart disease, and cancer outweigh the benefits significantly regarding smoking and UC. Other treatments for UC are much safer than continuing smoking.
- NSAIDs and the combined oral contraceptive pill (COCP) should be avoided as they have been associated with worse outcomes in CD
- Patients with any recurrence of symptoms should seek medical help urgently
- Patients taking immunosuppressants with fevers, malaise, chills, sore throat, bruising, or mouth ulcers should seek medical help as they may be indicators of serious drug side effects (e.g. myelosuppression)
Toxic megacolon
describes severe dilation of the colon (megacolon) accompanied by features of systemic toxicity, such as shock (toxic). Inflammation and damage to the colon wall are thought to lead to damage to the musculature and neurovascular supply, leading to paralysis of the affected segment and loss of smooth muscle tone, leading to dilation
causes of toxic megacolon
- Inflammatory bowel disease (IBD), particularly ulcerative colitis (UC) – the most common cause
- Clostridioides difficile infection
- Colonic ischaemia
- Diverticulitis
- Volvulus
- Immunosuppression – due to the increased risk of cytomegalovirus infection
- Antidiarrhoeal drugs (e.g. loperamide)
toxic megacolon presentation
Patients tend to present with abdominal symptoms and signs of shock:
- Abdominal pain and tenderness
- Abdominal bloating
- Abdominal distention
- Fever
- Tachycardia
- Hypotension
investigations for toxic megacolon
Full blood count:
- May show leukocytosis suggesting infection
- Acute blood loss or chronic disease may cause anaemia
Urea and electrolytes (U&Es):
- May show electrolyte abnormalities such as hypokalaemia secondary to diarrhoea
Serum lactic acid:
- May be elevated in bowel ischaemia
Stool sample testing:
- May show evidence of Clostridioides difficile infection
Abdominal x-ray:
- Often performed as an initial investigation
- Shows a dilated bowel
Chest x-ray:
- Can rule out bowel perforation, which may show free air under the diaphragm
Abdominal CT:
- Can help with diagnosis and shows a dilated colon with a loss of normal haustral markings
management of toxic megacolon
- Making the patient nil-by-mouth
- Resuscitation with IV fluids
- Broad-spectrum IV antibiotics, particularly if an infective cause is suspected
- For IBD: IV corticosteroids are often used
- Surgery – usually considered after 72 hours of medical management
- This is usually an abdominal colectomy with end-ileostomy
- This may result in the patient requiring a temporary or permanent stoma
complications of toxic megacolon
- perforation
- sepsis
Carcinoid syndrome
describes a paraneoplastic syndrome secondary to carcinoid tumours. These are rare and slow-growing neuroendocrine tumours, that release serotonin into the systemic circulation, leading to carcinoid syndrome.
carcinoid syndrome risk factors
Risk Factors
- Family history
- Multiple endocrine neoplasia (MEN) 1
presentation of carcinoid syndrome
Patients tend to present with diarrhoea and flushing due to the release of serotonin. Features include:
- Diarrhoea
- Flushing
- Bronchoconstriction
- Vague abdominal pain
- Hepatomegaly – suggests hepatic metastases
- Right-sided heart disease (e.g. tricuspid valve regurgitation), particularly if there are hepatic metastases
- Left heart disease in those with pulmonary metastases
investigations for carcinoid syndrome
Urinary 5-hydroxyindoleacetic acid (5-HIAA):
- This is the main metabolite of serotonin
- Increased levels are seen
management of carcinoid syndrome
Management may involve surgery, somatostatin analogues (e.g. octreotide, which works by blocking serotonin release), chemotherapy, and radiotherapy.
