Dyschezia, tenesmus and constipation Flashcards
Dyschezia definition
= difficult or painful defection ± blood (haematochezia)
Tenesmus definition
= excessive straining to pass stools
Constipation definition
= infrequent or difficult passage of stools associated with retention of faeces within the rectum & colon
Causes of dyschezia
- colon impaction: bones/tumour
- perineal hernia & rectal diverticulum
- rectal stricture
- anal neoplasia
- severe prostatomegaly
- obstipation
i.e. mainly lesions near the anal region
Why can severe prostatomegaly cause dyschezia?
- when the prostate enlarges, it goes upwards and dorsally and presses on the rectum, hence dyschezia
Causes of tenesmus
- colitis
- bone ingestion
- rectal/anal tumours
- post-op following perineal surgery
- prostatomegaly
What can tenesmus lead to?
- rectal prolapse
Colitis - CS
- tenesmus
- soft stools
- mucus in stool
- fresh blood
- generally well animal
Colitis - tx
- antibiotics which are specific for the bacterial population of the large bowel -> metronidazole, suphasalazine
- high fibre feed
- occasionally steroid (e.g. in severe ulcerative colitis)
‘Constipated’ dogs
- few truly constipated dogs
- a low have tenesmus & dyschezia however
– bones
– pelvic fractures
– rectal/anal tumours
The vast majority of dogs in the consulting room with ‘constipation’, have colitis or tenesmus/dyschezia for a mechanical reason
History q’s
- when did it start?
- what are they passing?
- is there any mucus/blood?
- any change in diet or access to bones/FB?
- are they eating?
- any v+?
- any trauma?
- any weight loss?
- any excessive licking of perineum or scooting?
Clinical exam
- assess demeanour and hydration
- nose to tail exam
- assess abdomen for any palpable gas or faecal excess
– colon palpable in dorsocaudal abdomen - check temperature
- rectal exam
– cats likely to require sedation/GA
Investigation
- rectal exam
- abdominal x-ray ± contrast (barium enema)
- US
- colonoscopy (need enema before)
- CT
- blood work: hydration, T, anaemia, WBCc, electrolytes, Tli/folate/cobalamin
- urinalysis: some Os assume constipation when the animal is actually straining to urinate, esp cats
Treatment
Cause dependent
High fibre or low residue diets
- low residue: highly digestible so very little waste produced so gives the bowels a rest when recovering from an episode
Metronidazole/sulphasalazine
Enema
- micro vs soapy water
- if have bony spicules stuck in their rectum
Surgery
- perineal herniorrhaphy
- anal sacculectomy: neoplasia
- subtotal colectomy
- rectal pull through
Pelvic fracture repair
Laxatives
- lactulose
- liquid paraffin
- micro-enema
Feline idiopathic megacolon - what is it? CS
- recurrent constipation & hypomotility of colon
- dilation of colon
- permanent loss of colonic structure & function
Feline idiopathic megacolon - causes
Mainly
1. idiopathic
2. pelvis fracture
3. sacral spinal deformity
4. aganglionosis
Feline idiopathic megacolon - signalment
- often overweight cats
- often house cats with an inactive lifestyle
Feline idiopathic megacolon - diagnosis
Radiography
- diameter o the colon is 1.5x length of 7th lumbar vertebrae
Feline idiopathic megacolon - tx
- laxatives
- enemas
- high fibre feed
- subtotal colectomy
Subtotal colectomy - risks, AB use, other comments
- high risk of infection (colon contains ++ bacteria: more than x10^10 per gram of faeces)
- antibiotic usage: cephalosporins/metronidazole
- don’t perform pre-op enema
- consider prolonged lag phase of healing and high intraluminal pressures increasing risk of dehiscence
- try to preserve the ileocecal junction if possible as gives better outcome
