Constipation (GI) Flashcards
What is chronic constipation?
Polysymptomatic heterogeneous disorder
Define constipation.
Defecation that is unsatisfactory characterised by:
- infrequent stools
- difficult stool passage (straining/discomfort)
- infrequent and/or difficult defecation (seemingly incomplete)
What is the difference between primary and secondary constipation?
- primary constipation - disordered regulation of colonic and anorectal neuromuscular function + brain-gut neuro-enteric function
- issues with the gut itself
- secondary constipation - metabolic disturbances, medicines, neurological disorders, spinal cord lesions, primary diseases of the colon e.g. cancer
- due to other conditions/exogeneous substances
What are some types of primary constipation? (3)
- slow-transit constipation: inadequate defecatory propulsion caused by primary dysfunction of colonic smooth muscle (myopathy) and/or its innervation (neuropathy)
- dyssynergic defecation: paradoxical contraction/inadequate relaxation of the pelvic floor muscles during attempted defecation, e.g. due to faulty toilet training, behavioural problems, or parent-child conflicts
- irritable bowel syndrome-constipation: altered autonomic regulation, release of NTs e.g. serotonin or altered functions of gut receptors
What is rectocele?
Associated with constipation - prolapse where the supportive wall of tissue between the rectum and vaginal wall weakens
Which gender is constipation more common in?
F > M
What is primary constipation caused by?
Most commonly due to poor diet (lack of fibre) or dehydration and insufficient exercise
What is secondary constipation caused by? (8)
- colorectal cancer
- bowel obstruction
- diverticulosis
- diverticulitis
- haemorrhoids
- IBS
- hypothyroidism
- drug-induced (opioids) etc
What is the main clinical feature of constipation?
Passage of infrequent hard stools
What are the key diagnostic/clinical features of constipation? (5)
- infrequent stools
- difficult defecation
- tenesmus - sense of incomplete evacuation
- excessive straining
- hard stools
What clinical features might be seen on examination of constipation?
- abdominal mass (RLQ/LLQ) on palpation - may indicate secondary cause
- anorectal lesions/abnormalities on DRE
- relaxation of the external anal sphincter and/or puborectalis muscle, together with perineal descent on defecation manouevre - abnormal may suggest evacuation disorder e.g. dyssynergic defecation
What are some risk factors for constipation?
- female
- age>65
- African ancestry
- lower socioeconomic status
- Fx
- sedentary lifestyle
- low fibre intake, inadequate calories/fluid (hardens stool, reduces transit)
- surgical procedures + childbirth
- medications - opiates, calcium channel blockers, TCAs (co-codamol commonly causes constipation as side effect)
What problem with the urinary system can constipation cause?
Outflow obstruction and trigger episodes of urinary retention in patients with enlarged prostates
What examinations do we conduct for constipation?
- abdominal examination
- digital rectal examination
What main investigation do we do for constipation?
Anal manometry to evaluate constipation or functional anorectal pain
