Irritable Bowel Syndrome

Question 1

Describe factors thought to contribute to the development of IBS.

Answer 1

Cause not fully understood. May result from disturbance of colon motility.

Factors such as visceral hypersensitivity, neuromuscular dysfunction, physiological conflicts and diet may play role.

Illness often starts after episode of gastroenteritis or stress.

Potential triggers could include:
Antibiotic therapy.
Pelvic surgery
Psychological stress/trauma.
Mood disturbance, anxiety, depression.
Sexual, physical or verbal abuse
Food intolerance
Eating disorders.

Question 2

Describe the epidemiology of IBS.

Answer 2

Common,
prevalence 10–20% of adults.
2:1 ratio F:M.

Question 3

Describe what a patient presenting with IBS would complain of.

Answer 3

At least 6 month history abdominal pain (often colicky, in the lower abdomen and relieved by defecation or flatus).

Altered bowel frequency with at least 3 bowel motions daily or less than 3 motions weekly.
Abdominal bloating.

Change in stool consistency.

Passage with urgency or straining.
Tenesmus.

Screen for ‘red flag’ alarm symptoms:
. weight loss;
. anaemia;
. PR bleeding;
. late onset (older than 60 years).
▶️Presence of any of the above requires referral to exclude colonic malignancy.

Question 4

What would be found on examination of a patient with IBS?

Answer 4

Normally nothing on examination.

In some cases the abdomen may appear distended and be mildly tender to palpation in one or both iliac fossa.

Question 5

Give some possible non-GI manifestations of IBS.

Answer 5

Gynaecological symptoms: dysmenorrhea, dyspareunia, premenstrual tension.

Urinary symptoms: Frequency, urgency, nocturia, incomplete bladder emptying.

Others: back pain, headaches, bad breath, unpleasant taste in mouth, poor sleeping, fatigue, anxiety, depression.

Question 6

What investigations would you perform on a patient thought to have IBS?

Answer 6

Diagnosis mainly from history but it may be vital to exclude organic pathology.

Blood: 
FBC (for anaemia), 
LFT, 
ESR, 
CRP, 
TFT. 
Anti-endomysial or anti-transglutaminase antibodies (to exclude coeliac disease).

Stool examination:
Microscopy and culture for parasites, cysts and infection.

Ultrasound:
To exclude gallstone disease.

Hydrogen breath test:
To exclude dyspepsia associated with Helicobacter pylori.

Endoscopy:
Upper GI endoscopy, sigmoidoscopy or colonoscopy if other pathologies suspected.

Question 7

How would you manage a patient with IBS?

Answer 7

Advice:
•Explanation and support with establishment of a positive doctor–patient relationship.
•Dietary modification (e.g. reducing dietary insoluble fibre) may help with constipation
—other approaches include exclusion diets and use of probiotics.

Medical:
According to the predominant symptoms:
. antispasmodics (e.g. mebeverin, buscopan);
. prokinetic agents (e.g. domperidone, metoclopramide);
. antidiarrhoeals (e.g. loperamide);
. laxatives (e.g. lactulose);
. low-dose tricyclic antidepressants (may # visceral awareness).

Psychological therapies: 
Often beneficial (e.g. cognitive–behavioural therapy, relaxation and psychotherapy).

Question 8

What are the complications associated with IBS?

Answer 8

Physical and psychological morbidity.

⬆️ Incidence of colonic diverticulosis.

Question 9

What is this prognosis like for patients with IBS?

Answer 9

A chronic relapsing and remitting course, often exacerbated by psychosocial stresses.

Question 10

Define IBS.

Answer 10

A functional bowel disorder defined as recurrent episodes (in the absence of detectable organic pathology) of abdominal pain/discomfort for at least 6 months of the previous year.

associated with two of the following:
. altered stool passage;
. abdominal bloating;
. symptoms made worse by eating;
. passage of mucous.