IBS Flashcards
definition of IBS
functional bowel disorder defined as recurrent episodes (in absence of detectable organic pathology) of abdo pain/discomfort for >=6mo of previous yr associated with 2 of:
- altered stool passage
- abdo bloating
- symptoms made worse by eating
- passage of mucus
aetiology of IBS
disorders of intestinal motility, enhanced visceral perception, microbial dysbiosis, psychosocial factors (stress) or food intolerance (lactose)
RF:
- physical and sexual abuse
- PTSD
- age <50yrs
- female
- previous enteric infection
- FH
epidemiology of IBS
prevalence 10-20%
age onset <=40yrs
female more
sx of iBS
>=6 month history abdominal pain (often colicky, in the lower abdomen and relieved by defecation or flatus).
altered bowel freq - >=3 motions daily/<=3 weekly
abdo bloating
change in stool consistency
mucus PR
passage with urgency/straining
tenesmus
worsening of symptoms after food
screen for red flag: weight loss, anaemia, PR bleeding, late onset >=60yrs - need referrel to exclude colonic malignancy
symptoms are chronic - exacerbated by stress, menstruation or gastroenteritis (post-infectious IBS)
dx of IBS
recurrent abdo pain/discomfort with at least 2 of
- relief by defecation
- altered stool form
- altered bowel freq - constipation and diarrhoea may alternate
signs of ibs
may be normal
general abdo tenderness is common (in one or both IF)
may be distended
insufflation of air during lower GI endoscopy (not usually needed) may reproduce the pain
ix of IBS
mainly from history, but may be vital to exclude organic pathology
blood
- FBC - anaemia
- LFT, ESR, CRP, TFT
- anti-endomysial or anti-transglutaminase Ab to exclude coeliac
- B12
- folate
- faecal calprotectin
stool - microscopy and culture for parasites, cysts and infection
US - exclude gallstone disease
hydrogen breath test - exclude dyspepsia associated with H pylori
Upper GI endoscopy, sigmoidoscopy or colonoscopy if other pathologies suspected.
exclude ovarian cancer - serum CA-125
endometriosis mimics IBS - consider if pain is cyclical
advice for IBS
explanation and support with establishment of a positive dr-pt relationship
dietary modification - reduce insoluble fibre may help with constipation (increased fibre intake can worsen flatulence/bloating so avoid insoluble fibre, such as bran; oats are better).
exclusion diets and probiotics
adequate water intake
promote physical activity
Combination probiotics in sufficient doses (eg VSL#3®) may help flatulence or bloating. Diets low in fermentable, poorly absorbed saccharides and alcohols may provide benefit (the low FODMAP diet).
medical mx of ibs
according to the predominant symptoms
antispasmodics - mebeverin 135mg/8h, buscopan for colic/bloating or hyosine butylbromide 10mg/8hr
prokinetic agents eg domperidone, metoclopramide
antidiarrhoeals eg loperamide 2mg after each loose stool
laxatives eg lactulose (worsens bloating)
low-dose tricyclic antidepressants - may reduce visceral awareness eg amitriptyline 10–20mg at night (SE: drowsiness, dry mouth)
for constipation: advice, then laxatives then prucalopride, linaclotide, or lubiprostone; or self-administered anal irrigation.
for diarrhoea: avoid sorbitol sweeteners, alcohol, and caffeine; reduce dietary fibre content, identify trigger foods
psychological therapies for ibs
CBT
relaxation and psychotherapy
hypnosis
emphasise the positive - excluded sinster things and over time condition tends to improve
refer ibs if
diagnostic uncertainty
changing symptoms in known IBS
refractory to management - stress/depression or refractory symptoms
chronic pain overlap syndromes - fibromyalgia, and chronic fatigue and chronic pelvic pain)
detrouser problems
complications of ibs
physical and psychological morbidities
increased incidence of colonic diverticulitis
px for ibs
a chronic relapsing and remitting course
exacerbated by psychosocial stresses
