8. Constipation and Tenesmus

Question 1

Define Constipation?

Answer 1

Difficulty In defecating with the retention of faece’s In the colon/rectum

Question 2

Define Tenesmus?

Answer 2

Straining to defecate

Question 3

Define Dyschezia?

Answer 3

Difficult defecation

Question 4

Define Haematochezia?

Answer 4

Blood in faeces

Question 5

Define Obstipation?

Answer 5

Severe prolonged constipation refractory to control

Question 6

Clinical signs?

Answer 6

• Tenesmus, dyschezia, haematochezia
• Non-productive or minimal amounts of faeces passed

Question 7

What are the differentials for tenesmus?

Answer 7

• Conslipatron
• • Anal gland disorders
• • Urinary tract disorders
• • Rectal and perineal disease
• • Prostatic disease

Question 8

What are the differentials for constipation?

Answer 8

Gastrointestinal disease

• Foreign body
• Rectal neoplasia and polyps
• Idiopathic (cats) - motility dysfunction
• Rectal strictures

Question 9

what are the differentials for constipation?

Answer 9

Extra-gastrointestinal Disease:
• Dietary- bones
• Dehydration
• Drugs- oploids, diuretics, antacids, antihistamine
• Electrolyte abnormalities:
» Hypercalcaemia, hypokalaemla
• Narrowing or compression of the colon:
»- Prostatic disease
• Rectal/perineal disease
• Sublumbar lymph node enlargement
• Pelvic canal narrowing (trauma, neoplasia,
malunion)
• Hypothyroidism
• Neurologlcal: Spinal cord disease
»- Cauda equine syndrome
»- Dysautonomia
• Aversion to litter tray (cats)

Question 10

Diagnostics of constipation and tenesmus?

Answer 10

• Watching defecation behaviour
• Bladder palpallon, especially In cats to rule out obstructive disease
• Rectal palpation (anal glands, rectum, prostate)
• Neurological examination
• Haematology, biochemistry and electrolytes
• radiographs:
• Confirm constipation, assess prostatic size, position of colon (narrowing)
• Megacolon: Colon Is > 1,5 x width of L7
• Ultrasound of prostate/sublumbar lymph nodes
• +/- Colonoscopy to assess for strictures and intraluminal masses

Question 11

Explain Feline constipation?

Answer 11

• Can be a result of or lead to megacolon
• Mega colon is a syndrome of severe irreversible dilation and hypomotitity of the colon
• Two forms of megacolon:

1. Dilation (idiopathic):

Most common form of megacolon approximately 70% of cases

• Due to end stage dysfunction of the colon typlcally seen in older cats
• Likely due to Impaired smooth muscle function, but possibly due to electrolytes abnormaflties
• Rule out obstructive lesions

2.Hypertrophy.
• Secondary to outflow obstruction: Pelvic narrowing, rectal strictures, tumours, foreign bodies

Question 12

treatment(all cases)

Answer 12

• Need to correct underlying dehydration and electrolyte imbalances
• Correction of underlying disease process

Question 13

Treatment for mild condition?

Answer 13

Mild:
Can trial faecal softeners/ laxatives and increased dietary fibre
High-fibre diets:
• Non-absorbable and hydrophilic e.g. Hills r/d®, Psylllum husk 1-4 teaspoon PO SID-BIO (e.g.
Metamucil ®) ·
laxatives:
• Only in well hydrated patients that are eating and drinking
• Emollients: Facilitate mixing of fat and water in colon, detergent action e.g. coloxyl 50
Lubricants: Coat faeces to decrease· water absorption In colon e.g. laxatone gel
• Osmotic agents: Non-absorbable sugars e.g. Lactulose 0.5ml/kg PO BID·TID, polyethylene·
glycol 3350, ¼ teaspoon PO BID
• Stimulant agents: Create strong peristaltic action e.g. Senokot, Biscodyl
) Micro-enemas:
• Warm water or normal saline with KY lubricant 1:1
• Dioctyl sodium sulfosuccinate 5-10 ml/small dog or cat; 10-20 ml/medium sized dog and 20-30
ml/large dog
Microlax enema
• Lactulose enema 5ml/kg (cat) or 10ml/kg (dog} of a 3 parts lactulose and 7 parts water

Question 14

severe treatment condition?

Answer 14

Correction of fluid and electrolyte Imbalances
Enema:
Typicaly, under general anaesthesia
Commence antibiotic coverage
Manual evacuation of faeces via colonic irrigation
Can use warm tap water or isotonic saline
Can breakdown faeces·vla abdominal massage or blunt Instruments
May require multiple sessions

Question 15

What to do if recurrent constipation or megacolon?

Answer 15

Recurrent constipation or megacolon:
Correction of underlying cause If possible
Medical:
Combination of laxatives, high fibre or low residue diets and prokinetiic agents:
• Laxatives:
o Lactulose 0.5ml/kg PO BID· TID
o Polyethylene glycol 3350, ¾ teaspoon PO BID
• Dietary management:
o Can try low residue diets If high fibre diets do not work
o Encourage water drinking
o Wet food rather than dry food
Prokinetic agents:
o Cisapride 0.1·0.5 mg/kg PO BID, 30 minutes before a meal, stimulates entire
gastrointesllnal tract, may cause vomiting and diarrhoea
o Ranitldlne 2mg/kg PO BIO, variable effect, can be combined with cisapride
Surgical:
» If non-responsive to medical management then surgical assessment for subtotal colectomy or
correction of pelvic abnormalities, only if no megacolon exists