Constipation and IBD

Question 1

Define constipation

Answer 1

Infrequent passage of stools and sensation of incomplete emptying

Question 2

What questions should you ask kids that present with constipation?

Answer 2

How often?
How hard?
Is it painful?
Has there been a chance?

Question 3

What is normal stool frequency?

Answer 3

4/day -1/wk

depends on age and diet

Question 4

What chart can you use to assess stool consistency?

Answer 4

Bristol stool chart
1 - separate hard lumps = v constipated
2 - lumpy and sausage like = slightly constipated
3 - Sausage shape w cracks in surface - normal
4 - Smooth, soft sausage - normal
5 - soft blobs with clear cut edges = lacking fibre
6 - mushy consistency with ragged edges = inflammation
7 - liquid consistency w no solid pieces = inflammation

Question 5

What are other signs and symptoms of constipation apart from not being able to pass stool?

Answer 5

Irritability
Poor appetite 
Lack of energy 
Abdominal pain/distension 
Withholding/straining
Diarrhoea

Question 6

Why do some children get diarrhoea when they are constipated?

Answer 6

Diarrhoea can leak past hard constipated stool –> overflow soiling

Question 7

What are the causes of constipation in children?

Answer 7

Poor diet (insufficient fluids, xs milk)
Potty training/school toilet (avoiding public toilets)
Intercurrent illness
Medication e.g. opoids/antacids
FH
Psychological (e.g. anxiety about starting school)
Organic (e.g. Hirschspurg’s disease)

Question 8

What is the pathophysiology of hirschspurg disease?

Answer 8

Defective caudal migration of parasympathetic neuroblasts
Affected segments have absent Meissner and Auerback plexuses leading to inability of myenteric plexus to control intestinal wall muscles, spastic contractions –> stenosis, expansion of colon proximal to aganglionic section –> megacolon

Question 9

What is the viscous cycle of constipation in kids?

Answer 9

Kid becomes constipated, large hard stool causes fissures or anal pain when trying to pass stool –> withholding –> more constipation –> more pain etc.

Question 10

What is involved in treating constipation in kids?

Answer 10

Dietary - increase fibre, fruit, veg, fluids, decrease milk
Reduce aversive factors - correct height for child, not cold
Avoid punitive behaviour from parents
Reward good behaviour - sitting on toilet, even if they don’t defecate
Medications to soften stool and remove pain

Question 11

What medications are used to soften stool and stimulate defaecation?

Answer 11

Osmotic laxatives, e.g. lactulose
Stimulant laxatives, e.g. senna, picolax
Isotonic laxatives, e.g. movicol
For as long as needed, take as much as they need to go

Question 12

What are the advantages of using laxatives?

Answer 12

Non-invasive

Given by parents

Question 13

What are the disadvantages of laxatives?

Answer 13

Non-compliance

SEs

Question 14

What is impaction?

Answer 14

Presence of hardened fecal matter in rectum/colon due to constipation

Chronic fecal impaction is difficult to pass so can lead to more constipation and more impaction

Question 15

How do you treat impaction?

Answer 15

Empty impacted rectum and empty colon - lacatives

Maintain regular stool passage (laxatives and slow weaning off Rx)

Question 16

What is a classical presentation of CD?

Answer 16

Tends to be non-bloody diarrhoea
Abdominal pain
Pronounced weight loss and growth failure (as affect absorption –> anaemia, malabsorption, B12 deficiency)
Arthritis and extra-intestinal features may be present

Question 17

What complications do you often get in CD and why?

Answer 17

Fistulas/strictures/abscesses as the CD can extend throughout the whole intestinal wall

Question 18

What is a classic presentation of UC?

Answer 18

Bloody diarrhoea, mucus, abdominal pain, tenesmus
Rectal bleeding
Arthritis and extra-intestinal features

Question 19

What extra-intestinal features can you get in UC and CD?

Answer 19

Uveitis (UC), arthritis, PSC (UC), skin manifestations (e.g. erythema nodosum), episcleritis (CD), fatigue etc.

Question 20

What laboratory investigations should you do if you suspect IBD?

Answer 20

FBC & ESR - will show anaemia, thrombocytopenia, raised ESR
Biochem - stool calprotectin, raised CRP, low albumin
Do stool microbiology to rule out infections

Question 21

What is fecal calprotectin an indicator of?

Answer 21

Intestinal mucosal inflammation

Question 22

What definitive investigations should you do for IBD?

Answer 22

Radiology - esp CD: MRI/barium meal and follow through

Endoscopy - colonscopy, upper GI endoscopy, mucosal biopsy, capsule endoscopy, enteroscopy

Question 23

What are the main differences in where CD and UC present?

Answer 23

CD can be anywhere from mouth to anus, tends to be skip lesions and can affect full thickness of the intestinal walls (hence why you get fistulas/strictures etc.)

UC is limited to the colon, is continuous inflammation and only affects the inner most lining of the colon

Question 24

Where does CD most commonly affect?

Answer 24

Terminal ileum

Question 25

What does UC look like on endoscopy?

Answer 25

Inflamed, red mucosa, bleeding on contact with endoscope

Ulcers and ?pseudopolyps

Question 26

What does CD look like on endoscopy?

Answer 26

Discontinuous pattern
Pinpoint lesions
Cobblestone appearance
Fistulas/fissures

Question 27

What are the aims of treatment in IBD in children?

Answer 27

Induce and maintain remission
Correct nutritional deficiencies
Maintain growth and development

Question 28

How do you treat IBD in children?

Answer 28

Enteral elemental feeding +/- 5ASA (mesalazine) –> methotrexate for UC, azathioprine for CD –> biologics (infliximab) –> surgery (e.g. proctocolectomy for UC and ileostomy for CD)