Irritable Bowel Syndrome

Question 1

what is irritable bowel syndrome?

Answer 1

Presence of abdominal pain or discomfort with altered bowel habits

Question 2

what is the difference between IBS and IBD?

Answer 2

Irritable Bowel Syndrome does NOT have inflammation in the GI tract

Inflammatory bowel syndrome has inflammation in the GI tract

Question 3

What blood test could you do to differentiate between IBS and IBD

Answer 3

fecal calprotectin ➔ is positive when there is inflammation in the GI tract ➔ IBD

Question 4

Who is most likely to have IBS?

Answer 4

it is one of the most commonly diagnosed GI diseases
- many ppl with IBS don’t seek medical care

more in the younger population - prevalence decreases with age
more in females vs males

Question 5

What causes IBS?

Answer 5

not well understood
a combination of
1. genetics ➔ gut-brain axis
2. environment ➔ gut infection, altered microbiome, diet sensitivity
3. psychosocial factors ➔ anxiety, depression, dysregulated stress response

Question 6

Explain the pathophys of IBS (2 pathways; not well elucidate)

Answer 6

1. altered bowel motility
   - gut-brain axis ➔ increase or decreasing movement, as a result of altered quantity or activity of serotonin
2. altered visceral bowel sensation
   - visceral hypersensitivity, increased feeling of visceral movements

Question 7

What is the classic feature of IBS?

Answer 7

bowel movement relieved abdo pain

Question 8

what are common s/s we’d expect to see in a IBS pt? (top 3)

Answer 8

1. constipation/bloating (gas) ➔ bc decreased bowel motility, more time to absorb water + ferment
2. diffuse abdo pain ➔ increased number of pain and stretch receptors in gut
3. bowel distension and diarrhea ➔ increased bowel motility ➔ increases peristalsis so more pain

Question 9

what are some red flag s/s we need to be aware of as an indicator for more sinister pathologies?

Answer 9

1. older onset (>50) ➔ query potential malignancy
2. constitutional s/s ➔ wt loss, night sweats
3. family history of GI diseases/maliganancies
4. nocturnal diarrhea
5. rectal bleeding
6. iron def anemia ➔ query a potential bleed

Question 10

What criteria is used to dx IBS?

Answer 10

Rome IV criteria
1. does the pt have recurrent abdo pain at least 1 day per week in the last 3 months associated with one of the following: 1) onset of s/s related to defecation, 2) onset of s/s associated with a change in freq of stool, or 3) onset of s/s associated with a change in form of stool

IBS-D: diarrhea form
IBS-C: constipation form
IBS-M: mixed

Question 11

When would we consider diagnostic ix for IBS pts?

Answer 11

when they have red flag s/s, otherwise it’s not indicated to do ix

Question 12

what ix should we consider if IBS pts are displaying red flag s/s?

Answer 12

ddx of celiac or IBD/CRC and other presenting s/s

1. consider anti-tTG and anti-EMA re: celiac
2. colonoscopy and biopsy ➔ UC/CRC
3. endoscopy and biopsy ➔ CD
4. other bloodwork to consider ➔ CBC, metabolics, inflammatory markers
5. with diarrhea s/s consider parasite/infectious workup

Question 13

how would you manage IBS?

Answer 13

it’s a symptom-based disorder ➔ so would treat s/s

1. advise on lifestyle modifications (diet: identify trigger foods, refer to a dietician, try low FODMAP diet; increase exercise; consider psychosocial counselling for underlying anxiety/mood disorders + to develop stress management strategies)
2. can consider medicinal therapies
   - mostly laxatives or bulking agents/antidiarrheals
   - not really done, but could consider tricyclic antidepressants (good for diarrhea) and SSRIs (good for constipation) for visceral hypersensitivity