IBD, constipation, Hirschprungs & CDH

Question 1

What is Crohn’s disease? Epidemiology?

Answer 1

Chronic inflammatory GI disease characterised by transmural (deep into mucosa) granulomatous inflammation affecting any part of the gut from mouth to anus - in particular the terminal ileum and proximal colon.
- Compared to UC there is unaffected bowel between areas of active disease (SKIP LESIONS).
- Affects females more
Ddx - Ulcerative colitis

Question 2

Clinical presentation of Crohn’s?

Answer 2

1) Growth failure
2) Delayed puberty
3) Classical presentation - abdominal pain, W/L, diarrhoea
4) Fever and lethargy
5) Older children may have lethargy and general ill health WITHOUT GI symptoms
6) Extra-intestinal symptoms - uveitis, oral lesions, arthralgia

Question 3

Diagnosis of Crohn’s?

Answer 3

1) Faecal Calprotectin - indicated IBD but not specific
2) Raised ESR, CRP (not specific)
3) Iron-Deficiency anaemia
4) Colonoscopy - biopsy will show non-caseating epithelioid cell granulomata with transmural infiltration, imaging will show skip lesions and bowel wall thickening

Question 4

Treatment of Crohn’s (remissions)?

Answer 4

1) Remission induced with nutritional therapy:
Normal diet replaced with whole protein modular feeds (polymeric diet) for 6-8 weeks (effective in 75% cases) - systemic steroids (Prednisolone) if diet ineffective.

2) Relapses require immunosuppressants: Azathioprine/Methotrexate, and anti-tumour necrosis factor agents - Infliximab when conventional therapy fails.
3) Supplementary nutrition via NG tube or gastrostomy
4) Surgery: obstruction, fistulae, abscess formation or severe localised disease that’s unresponsive to medical treatment.

Question 5

What is Ulcerative Colitis? RF and epidemiology?

Answer 5

• Recurrent, inflammatory and ulcerating disease involving the colonic mucosa, may effect the entire colon up to the ileocaecal valve.
• Differs from Crohn’s as it is never proximal to the IC valve, not transmural and NO SKIP LESIONS.
• Affects males and females equally, and appendicectomy before 20 yrs appears to be protective.
• RF: FH, chronic stress and depression
  Increased risk of adenocarcinoma of the colon in adults - regular colonoscopies screening is performed after 10 years from diagnosis.

Question 6

Pathophys of UC? Ddx?

Answer 6

Restricted to colonic mucosa (as opposed to transmural in Crohn’s), and begins at the rectum up to the ileocaecal valve. There is always continuous inflammation with no skip lesions.

Ddx? Crohn’s, Gastroenteritis

Question 7

Clinical presentation of UC?

Answer 7

1) Rectal bleeding
2) Diarrhoea
3) Colicky abdominal pain
4) Weight loss
5) Growth failure may occurs (less common that in Crohn’s)
6) Extra intestinal symptoms - erythema nodusum, uveitis, arthritis

Question 8

Diagnosis of UC?

Answer 8

1) Faecal Calprotectin - indicated IBD but not specific
2) Raised inflammatory markers - ESR, CRP
3) Iron-deficiency anaemia
4) Colonoscopy - biopsy shows mucosal inflammation, ulceration, goblet cell depletion.
NO granulomatas, NO skip-lesions, restricted to mucosa.

Question 9

Treatment of UC?

Answer 9

Mild - Aminosalicylates (Mesalazine), disease confined to rectum and sigmoid colon may be managed with topical steroids.
Severe -
-Systemic glucocorticoid steroids e.g. Oral Prednisolone
- Immunomodulatory therapy e.g. Azathioprine
If very severe with complications e.g. Toxic megacolon - surgery needed:
- Colectomy with ileostomy or ileorectal pouch.

Question 10

How is constipation defined?

Answer 10

The infrequent passage (< 3 stools a week) of dry, hardened faeces often accompanied by straining, pain or delay in defecation.

Question 11

Causes of constipation?

Answer 11

1) Poor diet - fibre
2) Poor fluid intake
3) Fear as a result of painful fissure
4) RARELY - Hirschprung’s disease (if FAILED to pass meconium in first 24 hours)

Question 12

Pathophysiology of constipation?

Answer 12

Painful defecation -> Voluntary withholding -> prolonged faecal stasis resulting in reabsorption of fluids and increase in size and consistency of stool -> more pain -> vicious cycle!

Question 13

Clinical presentation of constipation?

Answer 13

1) Large hard stool or ‘rabbit dropping’ stools
2) Distress/straining/bleeding with passage of stool
3) Abdominal pain
4) Overflow soiling - long-standing constipation has led to distention of rectum - loss of feeling the need to defecate causing diarrhoea overflow.

Question 14

Red-flags of constipation?

Answer 14

1) Failure to pass meconium within 24 hours of life - Hirschsprung’s?
2) Failure to thrive/growth failure - hypothyroidism, Coeliac disease
3) Gross abdominal distention - Hirschsprungs disease
4) Sacral dimple above natal cleft, hairy patch, central pit or discoloured skin - Spina bifida

Question 15

Treatment of constipation?

Answer 15

1) Encourage fluid and increase fibre intake
2) Disimpaction regime - stool softeners and laxative (Movicol), with escalating dose regimen over 1-2 weeks until impaction resolves
3) If unsuccessful try stimulant laxative - Senna
4) If unsuccessful consider enema/manual evacuation
5) Disimpaction must be followed by maintenance - Movicol slowly tapered down
Lifestyle advice - sit on toilet after meal, star chart reward for using toilet.

Question 16

What is Hirschsprung’s disease?

Answer 16

Congenital absence of ganglion cells from the myenteric and submucosal plexuses of part of the large bowel resulting in a narrow, contracted segment - functional GI obstruction.

Epidemiology: 1 in 5000 births and more common males.

Question 17

Clinical presentation of Hirschsprung’s disease?

Answer 17

1) Failure to pass meconium within first 24 hrs of life.
2) Abdominal distention and later bile-stained vomiting.
3) May present in infants severely as life-threatening Hirschsprung enterocolitis due to clostridium difficile infection.
4) Later childhood presents with chronic constipation associated with abdominal distention and growth failure.

Question 18

Diagnosis of Hirschsprung’s disease?

Answer 18

1) Suction rectal biopsy - absent ganglion cells and staining for acetylcholinesterase-positive nerve excess.

Question 19

Treatment of Hirschsprung’s disease?

Answer 19

Surgical - initial colostomy followed by anastomosing normally innervated bowel to the anus.

Question 20

Congenital Diaphragmatic Hernia - epidemiology? What is it?

Answer 20

• Developmental defect in the diaphragm allowing herniation of abdominal contents into the chest.
• Epidemiology: Rare, occurs in 1 in 2400 births, mainly diagnosed on antenatal ultrasound. Associated with other malformations: neural tube and trisomy 18 (Edward’s).
• Results in impaired lung development - pulmonary hypoplasia and pulmonary hypertension.

Question 21

Clinical presentation of congenital diaphragmatic hernia?

Answer 21

1) Difficult resuscitation at birth
2) Respiratory distress
3) Bowel sounds in one hemithorax, usually left so heart best heard on right.

Question 22

Diagnosis of congenital diaphragmatic hernia?

Answer 22

1) Prenatal ultrasound

2) Post natal - CXR (see loops of bowel in left chest and mediastinal displacement.

Question 23

Treatment of congenital diaphragmatic hernia?

Answer 23

1) Prenatal - consider foetal surgery
2) Postnatal - Insert large NG tube and suction to prevent distention of intra-thoracic bowel (to minimise pressure placed on mediastinal organs (e.g. heart and lungs).
- After stabilisation the hernia is repaired surgically.
- However, the main problem is the pulmonary hypoplasia - compression of lungs by herniated viscera results in stunted lung development - in those with hypoplasia - mortality is high.