Irritable Bowel Syndrome (IBS)

Irritable Bowel Syndrome (IBS)

·        Very common (up to 15 – 20%)

·        F > M

Symptoms & Signs

·        Crampy lower abdominal pain relieved by defaecation or flatus, associated with change in stool frequency/consistency

·        Diarrhoea (rarely at night) and mucus

·        Distension, variable abdominal tenderness

·        Nausea, heartburn, early satiety

·        Urinary frequency

·        Exacerbated by anxiety or stress

·        Age < 50 years

·        Feeling of incomplete evacuation

·        But NO blood, weight loss or recent onset

Diagnosis

·        A diagnosis of exclusion

·        Continuous or recurrent symptoms for at least 3 months

·        Abdominal pain relieved by defecation or associated with a change in bowel habit

·        Irregular pattern 25% of time with 2 or more of:

o  Change in frequency (> 3 per day or < 3 per week)

o  Change in form (lumpy/hard/loose)

o  Change in passage (straining/urgency/feeling of incomplete evacuation)

o  Mucus

o  Bloating/distension

Investigations

·        Exclude other conditions, e.g.:

o  FBC: anaemia and nutritional deficiency

o  LFT: exclude bilary colic 

o  Thyroid function: exclude myxoedema (® constipation) or thyrotoxicosis (® diarrhoea)

o  Colonic imagining for new or different symptoms in > 40 years – exclude cancer/IBD

o  Faecal fat, breath test, lactose tolerance test

·        Diagnosis of exclusion, so the differential is everything else

·        Cancer, IBD, diverticular/ceoliac disease, infection, diverticular disease, chronic pancreatitis, bilary/liver disease, peptic ulcer, motility disorder, bacterial overgrowth, laxative abuse, endometriosis, ovarian malignancy, thyroid disease

Aetiology

·        Abnormal gut motility

·        Enhanced visceral sensitivity

·        Psychological/psychiatric disorder

·        Food allergy/intolerance

Treatment

·        Supportive, reassurance, stress reduction,­fibre (RDA = 25 – 30 grams, average is 15), ­fluids (2 litres per day), ­exercise 

·        For constipation: bulking agents, lactulose

·        For pain relief: anticholinergics (cicyclomine), antispasmodics

·        For confirmed diarrhoea: antimotility drugs (loperamide, codeine phosphate)

·        If depressed then antidepressants