8.2 Irritable bowel syndrome Flashcards
What defines Irritable bowel syndrome and what is it caused by?
What are its characteristics?
IBS is a chronic, relapsing, functional bowel disorder that is of an unknown cause and is more common in females
Characterised by: abdominal pain or discomfort that is relieved by opening bowels
- may be associated with defaecation
- accompanied by a change in bowel habit (RED FLAG)
- may include disordered defaecation (IBSC or IBSD)
- abdominal distension or bloating
What are the 2 types of disordered defaecation and which is a red flag and why?
IBSC: C for constipation (not a red flag because it is generally not indicative of cancer, more common in females)
IBSD: D for diarrhoea (can be a red flag as it may indicate cancer, especially if it is “new diarrhoea” or in young people)
Give a common organic trigger that increases risk of IBS development and why
Bacterial gastroenteritis- it gets rid of our good bacteria and may cause damage to the “unstirred layer” of mucus on our intestinal lining or damage to villi. Overall there is a loss of protection which may lead to development of IBS
Post-bacterial gastroenteritis = 1/4 develop IBS
What is the classical clinical presentation of IBS (3)
1) Left Illiac Fossa pain
2) Relieved by opening bowels or passing wind
3) Unrelated to meals or other precipitating factors
What is used as the diagnostic criteria for IBS and what a the requirements of this criteria
Rome IV Diagnostic criteria:
At least 12 weeks, which need not be consecutive, in the preceding 12 months of abdominal discomfort or pain that has two of the three features:
1) relieved by defecation, and/or
2) associated with change of frequency of stool and/or
3) associated with change of consistency of stool
What is the FIRST diagnostic steps that should be taken on examination and how?
1) establish a symptom profile where:
A = Abdominal pain or discomfort B = Bloating C = Change in bowel habit
Identify any red flags (note there are associated red flags depending upon age)
When should we consider a diagnosis of IBS?
If person has abdominal pain or discomfort that is:
1) relieved by defaecation OR
2) associated with altered bowel frequency or stool form
Should be accompanied by at least 2 of the following:
1) altered stool passage (straining, urgency and incomplete evacuation)
2) abdominal bloating (F>M), distension, tension or hardness
3) symptoms made worse by eating
4) passage of mucus
and/or other symptoms which may include:
1) lethargy
2) nausea
3) bladder problems
4) back ache
Give the 4 most important RED FLAG symptoms
1) They are aged 40+ with unexplained weight loss and abdominal pain
2) They are aged 50+ with with unexplained rectal
bleeding
3) They are aged 60+ with Iron deficiency anaemia, changes in bowel habit or faecal occult blood (from screening)
4) They are aged UNDER 50 with rectal bleeding!!! OR abdominal pain, change in bowel habit, weight loss or Iron deficiency anaemia
What is the most serious differential diagnosis that should be ruled out before considering IBS?
Give 4 other potential differentials
Neoplasm!! (Cancer)
Other differentials may include:
- chronic constipation or chronic diarrhoea
- gynaecological disorders (eg. endometriosis)
- Intestinal parasites
- vascular Insufficiency (eg. ischemic colitis or abdominal angina)
If necessary why may we test the following?
Full Blood Count (FBC)
Erythrocyte Sedimentation Rate (ESR)
C Reactive Protein (CRP)
Liver Function Tests (LFTs)
To exclude:
anaemia
Iron deficiency
any inflammation
If necessary why may we test the following?
antibody testing
endomysial antibodies
tissue transglutaminase
For coeliac disease
If necessary why may we do a thyroid function test
to exclude as a cause
If there is inflammation what test may we perform and why?
Faecal Occult Bloods (three to six separate samples) In order to determine whether colonoscopy may be required
Give 4 other investigations that are not necessary (unless clinically indicated)
- ultrasound
- colonoscopy;
- barium enema
- hydrogen breath test (for lactose intolerance and bacterial overgrowth)
What is Faecal Calprotectin and according to NICE when is is recommended?
Faecal Calprotectin is a biochemical measurement of the protein calprotectin in the stool that is excreted via inflammatory processes into the intestinal lumen
Elevated faecal calprotectin indicates the migration of neutrophils to the intestinal mucosa and thus INFLAMMATION
NICE (2013):
‘Faecal calprotectin testing is recommended as an option to determine differential diagnosis of IBD or non-IBD (including IBS) in children with suspected IBD’
