GI presenting symptoms 2 Flashcards
(42 cards)
Diarrhoea
Increased stool water hence increased stool volume e.g. >200 mL daily which increases stool frequency and causes the passage of liquid stool.
If it is the fat content of the stool which is increased then use the term steatorrhoea – pale, malodourous stool that is difficult to flush.
Both should be distinguished from faecal urgency which suggests rectal pathology e.g. malignancy.
Diarrhoea - Classification
- Is this small or large bowel problem? – large bowel symptoms – watery stool ± blood and mucus, pelvic pain relieved by defecation, tenesmus and urgency. Small bowel symptoms – periumbilical or right iliac fossa pain not relieved by defecation, watery stool or steatorrhoea.
- Acute or chronic – if acute suspect gastroenteritis – ask about travel, change in diet and contact history. Chronic diarrhoea alternating with constipation suggests irritable bowel syndrome. Anorexia, weight loss, nocturnal diarrhoea or anaemia suggests an organic cause of diarrhoea.
Diarrhoea - Contents
- Bloody diarrhoea – can be caused by Salmonella, Shigella, Campylobacter, E coli, amoebiasis, UC, Crohn’s, malignancy, colonic polyps, pseudomembranous colitis or ischaemic colitis.
- Mucus – can occur in irritable bowel syndrome, colorectal cancer and colonic polyps.
- Pus – suggests inflammatory bowel disease, diverticulitis, a fistula or an abscess.
Diarrhoea - Non-GI Causes
- Drugs – antibiotics, proton pump inhibitors, cimetidine, propranolol, cytotoxics, NSAIDs, digoxin, alcohol or alcohol abuse.
- Medical conditions – thyrotoxicosis, autonomic neuropathy, Addison’s disease and carcinoid syndrome.
Diarrhoea - Examination
Look for weight loss, clubbing, anaemia, oral ulcers, rashes and abdominal scars.
Assess severity of dehydration – dry mucous membranes, decreased skin turgor and capillary refill >2 seconds.
Palpate for an enlarged thyroid or an abdominal mass and perform a rectal examination to look for masses (rectal carcinoma) or impacted faeces (overflow diarrhoea).
Also test for faecal occult blood.
Diarrhoea - Investigations
- Bloods – FBC (for iron deficiency or raised MCV in coeliac disease, alcohol abuse or ileal Crohn’s due to decreased B12 absorption), U+Es (for hypokalaemia), ESR (raised in malignancy or IBD), CRP (raised in infection or IBD), TSH (low in thyrotoxicosis) or coeliac serology.
- Stool – test for pathogens and Clostrisium difficile toxin (Pseudomembranous colitis). Test for faecal fat excretion or 13C-hiolein breath test (a much nicer test for measuring pancreatic exocrine function) if symptoms of pancreatitis, malabsorption or steatorrhoea.
- Rigid sigmoidoscopy – with biopsy of both normal and abnormal looking mucosa.
- Colonoscopy ± barium enema – to look for malignancy or colitis but avoid during acute attacks.
Diarrhoea - Management
Treat the cause where possible.
Practical issues – food handlers must not work until stool samples and negative and if there is an outbreak hospital wards may need to be closed.
Oral rehydration is better than IV but if impossible give 0.9% saline with 20mmol potassium per litre. In addition 30mg Codeine phosphate QDS or 2mg Loperamide after each loose stool (up to 16mg per day) can help reduce stool frequency.
Avoid antibiotics except in infective diarrhoea that is causing systemic illness due to the risk of antibiotic resistance.
C Diff - Definition and Toxin
A gram positive superbug whose spores are contagious - faecal-oral or from the environment where spores can live for extended periods and are difficult to eradicate.
Toxins – tissue culture, ELISA and PCR help detect the Clostridium difficile toxins.
C Diff - Signs and Carriage
- Signs – pyrexia, colic, diarrhoea ranging from mild to severe bloody diarrhoea with systemic upset – raised CRP and WCC, low albumin and colitis (with yellow, adherent plaques on inflamed non-ulcerated mucosa = the pseudomembrane) and possible multi-organ failure.
- Asymptomatic carriage – occurs in 1-3% of adults – risk factors are old age, being in hospital, >80% bed occupancy and antibiotic use (especially broad spectrum or IV antibiotics).
C Diff - Management
Stop the causative antibiotics where possible and if symptomatic give 400mg Metronidazole TDS for 10 days or 125mg Vancomycin QDS for severe disease.
In very severe cases e.g. toxic megacolon or raised lactate dehydrogenase a colectomy may be performed.
C Diff - Reoccurence and Spread
- Recurrent disease – repeat metronidazole once (overuse causes irreversible neuropathy). Probiotics can help prevent reoccurrences (not for immunosuppressed or if CVP line in situ).
- Preventing spread – meticulous cleaning, use of disposable gloves, not using rectal thermometers, hand washing and ward protocols e.g. bare below elbows.
Constipation - Definition and Criteria
Infrequent bowel movements (<3 times weekly) or passing stool less frequently than the patients normal habit or with difficult, straining or pain. Ask the patient exactly what they mean by constipation as bowel habits vary greatly between individuals and according to diet.
The Rome criteria – constipation is the presence of 2 or more of following during >25% of bowel movements – straining, lumpy or hard stools, sensation of incomplete evacuation, sensation of anorectal obstruction, manual manoeuvres needed to facilitate and <3 bowel movements per week.
Constipation - Causes
- General – poor diet, lack of exercise, dehydration, irritable bowel syndrome, old age, post-operative pain, hospital environment (e.g. lack of privacy) or distant or squalid toilets.
- Anorectal disease – anal fissure or stricture, rectal prolapse, mucosal ulceration or neoplasia or functional anorectal pain syndromes – proctalgia fugax and levator ani syndrome.
- Intestinal obstruction – colorectal carcinoma, strictures in Crohn’s disease, pelvic mass e.g. fetus or fibroids, diverticulosis (usually presents with bleeding) or pseudo-obstruction.
- Metabolic or endocrine cause – hypercalcaemia, hypothyroidism, hypokalaemia or porphyria.
- Drugs – opiates, tricyclic antidepressants, iron, antacids, diuretics e.g. furosemide and CCBs.
- Neuromuscular – slow transit from decreased propulsive activity – spinal or pelvic nerve injury, aganglionosis (Chagas’ or Hirschsprung disease), systemic sclerosis or diabetic neuropathy.
- Other – chronic laxative abuse, idiopathic slow transit, idiopathic megacolon or psychological.
Constipation - Features
Ask about frequency, nature and consistency of stools, whether there is mucus or blood present, does diarrhoea alternate with constipation, has there been a recent change in bowel habit, is there any pain and has there been a recent change in diet or medication?
A PR examination is essential!
Refer if there are atypical symptoms e.g. weight loss, abdominal pain or anaemia.
Constipation - Investigations
Indications for investigations are >40 years, change in bowel habit or associated symptoms – weight loss, PR mucus or blood or tenesmus.
Perform bloods – FBC, ESR, U+Es, Ca2+ and TFTs, sigmoidoscopy and biopsy of abnormal mucosa or is there is suspicion of colorectal malignancy perform colonoscopy or barium enema.
Constipation - Management
Often increased fluid intake and diet and exercise advice is all that is needed. A high fibre diet is often advised but can caused increased bloating without helping the constipation. Only progress to medication where above measures fail and try to use them for a limited period of time.
Medication options - bulking agent, stimulent or osmotic laxatives or stool softeners.
Constipation - Bulking Agents
Increase faecal mass so stimulate peristalsis. They must be taken with lots of fluid and can take a few days to take effect.
Contraindications – difficulty in swallowing, GI obstruction, colonic atony or faecal impaction.
Examples – bran powder (3.5g added to 2-3 meals per day – can inhibit absorption of trace elements if used with every meal), ispaghula husk e.g. Fybogel (3.5g sachet taken with water after meals), methycellulose e.g. Celevac (3-6 500mg tablets BD taken with >300mL water) or sterculia e.g. Normacol (10mL granules sprinkled onto food daily).
Constipation - Stimulent Laxatives
Increase intestinal motility so must not be used in intestinal obstruction or acute colitis. Avoid prolonged use as they can cause colonic atony, hypokalaemia or side effects such as abdominal cramps.
Examples – pure stimulant laxatives e.g. biscodyl (5-10mg at night) or senna (2-4 tablets per night) or mixed stimulant laxative and stool softener e.g. Docusate sodium.
In addition Sodium picosulphate (5-10mg 12 hours prior to procedure) can be used for rapid bowel evacuation.
Constipation - Osmotic Laxatives
Retain fluid in bowel.
Examples – lactulose (30-50mL BD causes osmotic diarrhoea of low faecal pH that discourages growth of ammonia producing organisms – so useful in hepatic encephalopathy), magnesium salts (e.g. magnesium hydroxide or sulphate are useful when rapid bowel evacuation is required) or phosphate enemas can be used for evacuation prior to procedures.
Constipation - Stool Softeners
Particularly useful in the management of painful anal condition e.g. an anal fissure.
Examples – Arachis oil enemas lubricate and soften impacted faeces.
Vomiting - Investigations
Do bloods – FBC, Us and Es, LFTs, Ca2+ and amylase.
Also do ABG as a metabolic alkalosis (hypochloraemic) can result from loss of gastric contents – pH >7.45 and raised HCO3- indicates severe vomiting.
Request a plain abdominal x-ray if you suspect bowel obstruction and an upper GI endoscopy if vomiting is prolonged and consider a CT head if you suspect raised ICP.
Vomiting - Management
Try to use pre-emptive therapy e.g. pre-operatively for post op symptoms. Try the oral route where possible but around a third of patients will require a 2nd line anti-emetic.
If patients are dehydrated also give IV fluids with potassium replacement and monitor electrolytes and fluid balance.
Anti-emetics
H1 antagonists - cyclizine or cinnarizine.
D2 antagonists - metoclopramide, domperidone or prochlorperizine.
5-HT3 antagonist - ondansetron.
Jaundice - Definition
Yellow pigmentation of the skin, sclerae and mucosa due to increased plasma bilirubin – visible at >35 μmol/L but not always easy to spot when mild.
Jaundice can be classified by the site of the problem – pre-hepatic, hepatocellular or obstructive (cholestatic) or by the type of circulating bilirubin – conjugated or unconjugated.
Kernicterus – this is seen in infants and involves deposition of unconjugated bilirubin in the basal ganglia which causes opisthotonus – hyperextension and spasticity.
