IBS Flashcards
What is IBS
Chronic, relapsing and often debilitating disorder of gut-brain interaction
What are possible Mechanisms
- Visceral hypersensitivity.
- Abnormal GI immune function.
- Changes in gut microbiome
- Abnormal autonomic activity.
- Abnormal central pain processing of afferent gut signals (altered ‘brain-gut interactions’).
Risk and contributing factors
- Co-morbidities
- GI infection
- GI inflammation, e.g. due to infection, IBD - Drugs, e.g. antibiotics
- Diet, e.g. alcohol, caffeine, spicy foods, fatty foods
- Psychological factors, e.g. stress, anxiety, depression
Diagnosis - no alarm symptoms and present for at least 6 months
- Abdominal pain or discomfort
- Bloating (more common in women)
- Change in bowel habit
3 criteria required for diagnosis
- Abdominal pain or discomfort for at least 6 months
- Is either relieved by defecation of associated with altered bowel frequency (increased / decreased), or stool form (hard, lumpy, loose, watery)
- Is accompanied by 2 or more of:
- Altered stool passage (e.g. straining, urgency, incomplete evacuation)
- Abdominal bloating, distension, tension or hardness
- Made worse by eating
- Passage of mucus
Diagnosis - classification
- IBS-C: Constipation-predominant IBS >25% hard stools, <25% loose stools
- IBS-D: Diarrhoea-predominant IBS (most common) > 25% loose < 25% hard
- IBS-M: Mixed, fluctuating between diarrhoea and constipation > 25% hard and loose
- IBS-U: Unclassified; symptoms meet criteria for IBS but don’t fall into one of the 3 subgroups
Bristol stool chart
Type 1-2 indicate constipation
Type 3-4 are ideal stools as they are easier to pass
Type 5-7 may indicate diarrhoea and urgency
Clinical assessment - Clinical History
Symptoms – onset, duration, type, severity (use Bristol chart)
Impact of symptoms on daily functioning (home, work, social, etc.)
Lifestyle
Diet (including fibre intake), nutrition, and any known food triggers
Physical activity
Alcohol intake
Smoking status
Psychosocial Hx. - Any recent stresses, anxiety, or depression
Medical Hx. – e.g. GI, psychological or previous surgery
Medication Hx. – e.g. those contributing to diarrhea / constipation
Signs of alternative diagnosis, especially alarm signs
Clinical assessment - Physical examination and investigation
Weight, BMI (check for unintended weight loss)
Palpate the abdomen for signs of tenderness or masses (abdominal examination)
Rectal examination to exclude perianal or rectal pathology
Full blood count (FBC) to exclude Anaemia or Raised platelet count
C-reactive protein (CRP) and / or Erythrocyte sedimentation rate (ESR)
to exclude Active inflammation, e.g. IBD, infection
Coeliac serology to exclude Coeliac disease
Faecal calprotectin to exclude IBD
Drugs causing diarrhoea
Magnesium-containing medicines, e.g. antacids
Antibiotics
PPIs / H2RAs
ACE-Inhibitors, e.g. lisinopril
Metformin
Levothyroxine
NSAIDs
Chemotherapy
Laxatives (inappropriate or prolonged use)
Iron
Drugs causing constipation
Opioids, e.g. morphine, codeine
Anticholinergics, e.g. tolterodine, hyoscine
Amitriptyline (TCA)
Verapamil / diltiazem
Beta-blockers, e.g bisoprolol
Aluminium-containing antacids
Iron
Non-GI symptoms
- Psychological
- Rheumatological
- uro- gynaecological
- neurological
- pulmonary
Lower GI – Alarm features!!
Unintentional and unexplained weight loss
Unexplained or uninvestigated rectal bleeding
Positive faecal immunochemical (FIT) test
Rectal or abdominal mass
Aged >60 with any of; change in bowel habit, raised faecal calprotectin, iron deficiency anaemia, abdominal pain
Persistent or frequent bloating in females (especially over 50)
Management Provide Information and support
Explaining diagnosis in context of the gut-brain axis and explaining that IBS is a chronic, relapsing condition which can be triggered by stress, intercurrent illness, medications, eating
Reassurance, e.g. not associated with increases risk cancer or mortality
Aim of management is to improve symptoms and quality of life
Signpost to sources of information and support,
- Management Diet and lifestyle
General dietary advice (personalised to individual):
–Regular meals, healthy balanced diet - take time to eat
–Avoid missing meals, long gaps, eating late at night
–Drink > 8 cups of fluid/day (water and non-caffeinated drinks)
–Restrict tea/coffee to 3 cups/day
–Reduce alcohol and fizzy drinks
–Reduce intake of ‘resistant starch’
–Limit fresh fruit to 3 portions/day (portion = 80g)
–Avoid sorbitol if diarrhoea
–Eating oats may help wind and bloating