Constipation

Question 1

Causes of constipation in children?

Answer 1

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

Question 2

Presentation of constipation?

Answer 2

Typical features in the history and examination that suggest constipation are:

Less than 3 stools a week
Hard stools that are difficult to pass
Rabbit dropping stools
Straining and painful passages of stools
Abdominal pain
Holding an abnormal posture, referred to as retentive posturing
Rectal bleeding associated with hard stools
Faecal impaction causing “overflow soiling”, with incontinence of 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?

Causes?

Answer 3

Encopresis is the term for faecal incontinence. This is not considered pathological until 4 years of age. It is 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.

Other rarer causes of encopresis include:

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

Question 4

Lifestyle factors that contribute to constipation?

Answer 4

There are a number of lifestyle factors that can contribute to the development and continuation of constipation:

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 5

Desensitisation of the rectum in constipation?

Answer 5

Often patients develop a habit of not opening their bowels when they need to and ignoring the sensation of a full rectum. Over time they loose the sensation of needing to open their bowels, and they open their bowels even less frequently. They start to retain faeces in their rectum. This leads to faecal impaction, which is where a large, hard 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, the more difficult it is to treat the constipation and reverse the problem.

Question 6

Secondary causes of constipation?

Answer 6

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

Question 7

Red flags in constipation?

Answer 7

Red flags are things in the history or examination that should make you think about serious underlying conditions that may be causing the constipation. These should prompt further investigations and referral to a specialist:

Not passing meconium within 48 hours of birth (cystic fibrosis or Hirschsprung’s disease)
Neurological signs or symptoms, particularly in the lower limbs (cerebral palsy or spinal cord lesion)
Vomiting (intestinal obstruction or Hirschsprung’s disease)
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 (coeliac disease, hypothyroidism or safeguarding)
Acute severe abdominal pain and bloating (obstruction or intussusception)

Question 8

Complications of constipation?

Answer 8

Pain
Reduced sensation
Anal fissures
Haemorrhoids
Overflow and soiling
Psychosocial morbidity

Question 9

Management of constipation?

Answer 9

A diagnosis of idiopathic constipation can be made without investigations, provided red flags are considered. It is important to provide adequate explanation of the diagnosis and management as well as reassure parents about the absence of concerning underlying causes. Explain that treating constipation can be a prolonged process, potentially lasting months.

NICE clinical knowledge summaries recommend:

Correct any reversible contributing factors, recommend a 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.