Approach to chronic diarrhoea and constipation Flashcards
List the 6 steps in the approach to diarrhoea
- History & physical examination
- Symptomatic therapy
- Laboratory investigations
- Diagnostic imaging
- Gastrointestinal biopsy
- Therapeutic trials
List the DDx for alimentary diseases that cause diarrhoea
- Adverse reactions to food: allergy, poisoning
- Inflammatory bowel disease
- Antibiotic responsive diarrhoea
- Lymphangiectasia
- Lymphoma/tumours
- Infectious diarrhoea
- Obstructions
What is Lymphangiectasia?
Lymphatic system within the SI is obstructed -> dilation of the lacteal
Diarrhoea due to protein loss into the intestine
List the DDx for systemic causes of diarrhoea
Liver disease
Renal disease
Pancreatic disease
Endocrine disease
- Addison’s disease
- Diabetes mellitus
- Hyperthyroidism
Describe the information which should be gathered when you are presented with a dog with diarrhoea
Gastrointestinal signs
Systemic signs
Diet history
Vaccine history etc
Verify vomiting vs regurgitation
Classify the diarrhoea - SI vs LI
Grade the severity of signs
Why should you check the tongue in the physical exam?
To check for a linear foreign body
Define haematochezia
Fresh blood in the stool
Why is it important to classify diarrhoea? How is this done?
- Helps with localisation
- Ask owner to bring in a sample of faeces
- Photo of the faeces
Describe the features of diarrhoea and clinical signs that enable it to be localised to the small intestine
- Increased volume
- Colour change
- Normal to slight increase in frequency
± Weight loss
± Flatulence, borborygmi, halitosis
Describe the features of diarrhoea and clinical signs that enable it to be localised to the large intestine
- Decreased volume
- Increased frequency
- Urgency & tenesmus
- Mucus & haematochezia
- Dyschezia: pain on defaecation
- Constipation ± variable consistency
- No weight loss?
What is the main function of the LI?
To act as a storage organ for appropriate defaecation, enabling the individual to make a conscious decision on when to defecate
Describe diffuse diarrhoea
Watery with some solid components
Fresh blood
Melaena is a sign of…?
Upper GI disease
Blood loss from stomach or SI -> blood gets digested
Dark stool – tar/black
Fibre supplementation is used for diarrhoea localised where?
Large intestine
How should a patient be managed/prepared before a colonoscopy?
Starve 48 hours
Poly-ethylene glycol:
- 3 doses, 4h apart
- Use Stomach tube
Followed by 2x warm water enemas
Which laboratory test is carried out first in diarrhoea cases?
Faecal analysis
What is being assessed on faecal analysis?
Parasites
Bacteria
Name 3 parasites which may be seen on a faecal analysis
- Giardia
- Cryptosporidia
- Tritrichomonas foetus (cats)
Describe the disease caused by Tritrichomonas foetus
- Poor bodily condition
- Chronic diarrhoea
- Most commonly affects pedigree cats and cats in colonies
- Causes SI diarrhoea in cats and LI diarrhoea in dogs
How is Tritrichomonas foetus diagnosed?
Faecal preparation in saline
Culture
Polymerase chain reaction
Describe the stage 2 laboratory tests carried out for diarrhoea cases
Haematology
Serum biochemistry
Urinalysis
Mainly used to rule out systemic diseases - Liver disease, Kidney disease, etc
Describe the endocrine tests used in diarrhoea cases
ACTH stim test/ Basal cortisol - hypoadrenocorticism
Total thyroxine - hyperthyroidism
What is the trypsin-like immunoreactivity test used for?
Exocrine pancreatic insufficiency
Which test could you carry out to diagnose pancreatitis?
Total lipase or pancreatic lipase
Folate and cobalamin tests are used to assess?
Malabsorption
What does a hypocobalaminaemia result indicate?
A negative prognostic indicator
If present treat with cobalamin
In cases of diarrhoea when is radiography useful?
Radiography is good for:
- Foreign bodies
- Masses
- Obstructions
In cases of diarrhoea when is ultrasound useful?
Can identify intestinal masses and lymph nodes
Describe how endoscopy is used in diarrhoea cases
Minimally invasive and direct examination
Requires equipment and expertise
Small superficial samples from a limited region
Harder to find a focal lesion
Smaller biopsy samples
Describe how a coeliotomy is used in diarrhoea cases
Can get multiple full-thickness biopsies
Surgical risk
Best for cats
A non-specific normal /mild inflammation result from a biopsy indicates what possible causes?
Adverse reaction to food
Antibiotic-responsive diarrhoea etc
IBD ~ “chronic enteropathy”
A moderate-severe inflammation result from a biopsy indicates what cause?
IBD ~ “chronic enteropathy”
Which two specific severe conditions can also be diagnosed from a biopsy?
Lymphoma
Lacteal dilation - Lymphangiectasia
What information would you ask owners to record in a diary?
Frequency of diarrhoea
Other signs – vomiting / pain
Appetite and demeanour
Compliance with treatment
Define constipation
Difficult, incomplete, or infrequent evacuation of dry hardened faeces from the bowels
List the possible causes of constipation
- Dietary
- Neuromuscular: idiopathic megacolon
- Obesity
- Hospitalisation
- Change in routine
- Inactivity
- Colonic obstruction: stricture, pelvic trauma, neoplasia
- Dehydration
- Drug-induced
How is constipation treated?
- Remove underlying cause if possible
- Oral laxatives i.e. lactulose
- Enemas
- Oral polyethylene glycol
- Gentle manual evacuation under anaesthetic
- Surgery (if megacolon)
- Dietary management: High fibre diet
