Functional dyspepsia & irritable bowel syndrome (IBS) Flashcards
Define irritable bowel syndrome.
IBS is a functional bowel disorder defined as recurrent episodes (in the absence of organic pathology) of abdominal pain and discomfort for >6months of the previous year, associated with two of the following:
- altered stool passage
- abdominal bloating
- symptoms made worse by eating
- passage of mucous
What is the aetiology of IBS?
The cause is not known; an organic trigger, such as bacterial gastroenteritis, is seen in some patients however there is undoubtedly a psychological component.
What is the pathophysiology of IBS?
Dysfunction of motor and sensory aspects of the GI tract
Altered gut reactivity (motility and secretion) in response to stimuli which may be..
- environmental - personal life stresses or abuse
- luminal - certain foods, bacterial overgrowth or toxins, gut distension or inflammation
… and this altered reactivity can lead to constipation/diarrhoea.
People with IBS may also have a lower threshold for pain (lower pressures cause pain) compared to people without IBS.
How common is IBS?
10-20% prevalence
More common in females (2:1)
Onset usually <40yrs
What is the typical presentation of IBS?
- >6 months of abdominal pain (often colicky, in lower abdomen, relieved by defecation or flatus)
- Altered bowel frequency - >3 bowel montions daily or <3 weekly
- Abdominal bloating
- Change in stool consistency
- Passage with urgency or straining
- Tenesmus - inclination to evacuate bowels
Screen for red flag alarm symptoms: weight loss, anaemia, PR bleeding, late onset (>60 years) = presence of any require referral to exclude colonic malignancy
IBS coexists with chronic fatigue syndrome, fibromyalgia, temporomandibular joint dysfunction.
Non GI features: gynae (dysmenorrhoea, dyspareunia), urinary (frequency, urgency, nocturia, incomplete bladder emptying), other (joint hypermobility, back pain, headache, bad breath, unpleasant taste in mouth, poor sleep)
What are the risk factors for IBS?
- Affective disorders e.g. depression, anxiety
- Psychological stress/trauma
- Age <50 years
- Female sex
- GI infection (30%)
- Abx therapy
- Sexual, physical, verbal abuse
- Pelvis surgery
- Eating disorders
What are the signs of IBS on examination?
- Abdominal tenderness - in RLQ or LLQ or normal.
- Distension
What investigations would you do for IBS?
Mainly diagnosis from history but may be vital to exclude organic pathology:
- FBC
- ESR/CRP
- EMA or TTG to exclude coeliac disease
Other:.
Bloods:
- LFT, ESR, CRP, TFT - should all be normal. CRP <0.5 mg/L makes IBD unlikely (and IBS more likely)
- Stool studies - MS&C for parasites, cysts and infection; faecal calprotectin <40 micrograms/g makes IBD unlikely (and IBS more likely).
Imaging
- AXR - normal, may show obstruction
Invasive:
- Flexible sigmoidoscopy and colonoscopy- abnormal mucosa suggest inflammatory bowel disease
How do you subtype IBS?
What is the management of IBS?
Conservative:
- Lifestyle and dietary modification - food (eliminate triggers like caffeine, lactose, or fructose, add fibre), low FODMAP diet, reduce stress. gradually increase fibre as it has been shown to be beneficial in IBS
- +/- Dietitian referral if no improvement
- Psychological therapies - e.g. CBT, relaxation and psychotherapy
Medical:
- Antispasmodics - cause colonic relaxation by anticholinergic action - e.g. mebeverine, metoclopramide
- Prokinetic agents - e.g. domperidone, metoclopramide
- Anti-diarrhoeals - e.g. loperamide
- Laxatives - e.g. conventional laxatives then linaclotide
- Low-dose TCA - may reduce visceral awareness
- Peppermint oil 30min before meals may reduce colonic spasm and bloating
‘Do not encourage use of acupuncture or reflexology for the treatment of IBS
What are the complications of IBS?
- Damage to family and work relationships
- Increased incidence of colonic diverticulosis
What is the prognosis with IBS?
75% of patients are helped by explanation and symptomatic relief.
Chronic relapsing and remitting course, often exacerbated by psychosocial stresses
But if no long term complications of the disease then normal life expectancy
What may need to be avoided in the diet to avoid diarrhoea?
Reducing fructose will help reduce diarrhoea predominant symptoms. If not well absorbed by the bowel, fructose can contribute to osmotic diarrhoea and increased flatulence.
Which of these is not a recommended treatment for IBS?
- CBT
- Hypnotherapy
- Antispasmodic agents
- Loperamide for diarrhoea
- Tricyclic antidepressant
- Acupuncture
Acupuncture
Name 2 anti-diarrhoeals.
Loperamide - no peripheral absorption; acts on miu opioid receptors to reduce gastric motility
What criteria may be used to diagnose IBS?
Rome II - NB: this differs from NICE as they only require symptoms to be present for 6 weeks
