GI - Constipation

Question 1

Definition

Answer 1

Most cases of constipation can be described as idiopathic constipation or functional constipation meaning there’s not significant underlying cause other than simple lifestyle factors.
Important to think about possible secondary causes of constipation = Hirschsprung’s disease, cystic fibrosis or hypothyroidism

Question 2

Presentation

Answer 2

How often someone opens their bowels varies between individuals - varies even more in breast-fed babies. Can be as little as 1 stool a week.
Typical features in history + examination that suggests constipation are:
- < 3 stools a week
- hard stools difficult to pass
- rabbit dropping stools
- straining and painful passages of stools
- abdominal pain
- holding an abdominal posture = retentive posturing
- faecal impaction causing overflow soiling, with incontinence particularly loose smelly stools
- hard stools may be palpable in abdomen
- loss of the sensation of the need to open the bowels

Question 3

Encopresis

Answer 3

Faecal incontinence = not considered pathological until 4 years of age. Usually a sign of chronic constipation where the rectum becomes stretched and looses sensation. Large hard stools remain in the rectum and only loose stools are able to bypass the blockage and leak out, causing soiling.

Question 4

Rarer causes of encopresis

Answer 4

Spina bifida
Hirschprung’s disease
Cerebral palsy
Learning disability
Psychosocial stress
Abuse

Question 5

Life style factors which cause constipation

Answer 5

Habitually not opening the bowels
Low fibre diet
Poor fluid intake and dehydration
Sedentary lifestyle
Psychosocial problems such as a difficult home or school environment (always keep safeguarding in mind)

Question 6

Desensitisation of the rectum

Answer 6

When Px develops habit of not opening bowels when needs + ignore the sensation of full rectum
Over time loose sensation of needing to open their bowels + open less often.
They start to retain faeces in their rectum.
Leads to faecal impaction = a large, heard stool blocks the rectum
Over time the rectum stretches as it fills with more and more faeces = this leads to further DESENSITISATION of the rectum.
The longer this goes on = more difficult it is got treat constipation and reverse the problem

Question 7

Secondary causes

Answer 7

Hirschsprung’s disease
Cystic fibrosis (particularly meconium ileus)
Hypothyroidism
Spinal cord lesions
Sexual abuse
Intestinal obstruction
Anal stenosis
Cows milk intolerance

Question 8

Red flag signs

Answer 8

• Not passing meconium within 48 hr of birth = CF or Hirschsprung’s
• Neurological s+s esp in lower limbs = cerebral palsy or spinal cord lesion
• Vomiting = intestinal obstruction or Hirschsprung’s
  Ribbon stool = anal stenosis
• Abnormal anus = anal stenosis, inflammatory bowel disease or sexual abuse
• Abnormal lower back or buttocks = spina bifida, spinal cord lesion or sacral agenesis
• Failure to thrive = coeliacs, hypoT or safeguarding)
• Acute severe abdominal pain and bloating = obstruction or intussusception

Question 9

Diagnosis

Answer 9

Idiopathic constipation = can be diagnosed without investigations (red flags must be considered)

Question 10

Management

Answer 10

• Correct reversible contributing factors + high fibre diet and good hydration
• Start laxatives (movicol is first line)
• Faecal impaction may require a disimpaction regimen with high doses of laxatives at first
• Encourage and praise visiting the toilet. This could involve scheduling visits, a bowel diary and star charts.
• Laxatives should be continued long term and slowly weaned off as the child develops a normal, regular bowel habit.