Constipation Flashcards
Definition
Difficulty emptying the bowels associated with hardened stool.
- For many patients its a chronic condition
Primary constipation
As a result of disordered or ineffective regulation of colonic and anorectal neuromuscular function or brain-gut neuroenteric function. = patients have slower transit of stool through the large bowel and difficulty evacuating the faeces
Secondary constipation
As a result of factors such as:
- certain medications (opiates, antipsychotics),
- metabolic disturbances (hypercalcaemia, hypothyroidism)
- neurolgical disorders - Parkinsons, spinal cord lesions
- primary diseases of the colon.
- Colonic disease: Hirschprungs, anal stricture, colorectal cancer, anal fissure
- Functional disorders: IBS, dyssynergic defecation
Epidemiology
- Female
- Age > 65
- Black
- Low socioeconomic status
- DM
- Sedentary lifestyle
- Reduced dietary fibre
Signs
- Abdominal mass: stool may be palpable in R/LLQ
- Anorectal lesions: haemorrhoids, fissures
- Abnormality on PR exam: hard stool, anal spasm, anal mass, anal stricutre
Symptoms
- Difficulty defecation: prolonged attempts
- Infrequent stools< 3 per week
- Unsatisfactory of incomplete emptying
- Excessive straining
- Hard stools
- Overflow diarrhoea
Diagnosis
Abdominal examination:
- masses
- distention
- palpable colon
PR exam:
- masses
- stool
- fissures
- haemorrhoids
- prolapse
- rectocele
Secondary investigations
- Bloods: fbc, tft, u+e, bone profile, blood glucose
- Abdo x-ray: faecal impaction, abdo masses
- Colonoscopy
Management = Short duration constipation (<3m)
FIRST LINE =
- Investigate and exclude secondary cause
- Lifestyle advice: increase daily fibre intake
- Bulk forming laxatives: fybrogel (ispaghula husk), methylcellulose
Second line (hard stool, difficult to pass):
- Osmotic laxative: macrogel, lactulose
Second line (soft stool, inadequate emptying):
- Stimulant laxatives: senna, bisacodyl
Management = Chronic constipation
If at least two laxatives from different classes tired at highest recommended doses for at least 6 months and failed to relieve symptoms:
- Prucalopride: prokinetic which stimulates GI motility
Faecal impaction:
- FIRST LINE = Oral macrogel +/- stimulant laxative
- Second line = suppository: bisacodyl, glycorel
- Third line = enema: sodium phosphate
Constipation
- Pain
- Delirium
- Anal fissure
- Haemorrhoids
- Rectocele
- Rectal ulcer syndrome
- Megarectum and megacolon: as a result of severe faecal impaction