How the bladder and bowel are connected
The bladder and rectum sit side by side in the small pelvis and are controlled by the same nerves and the same pelvic floor muscles. When the rectum is full of hard stool, it:
- presses on the bladder and reduces its capacity,
- irritates the bladder and causes sudden contractions,
- prevents the bladder from emptying completely,
- makes it easier for bacteria to enter the urinary tract.
That is why constipation is the most often overlooked cause of daytime wetting and bedwetting, urinary tract infections, and slow resolution of reflux. When these two problems occur together, it is called bladder and bowel dysfunction.
How to recognize constipation in a child
Suspect constipation if two or more of the following are present:
- fewer than 2 stools a week,
- hard, large, or lumpy stools like “pellets”,
- pain, crying or fear of the toilet during bowel movements,
- the child tries to hold in stool: squeezes the legs, hides in a corner,
- stool stains in the underwear,
- large stools that block the toilet.
The Bristol stool scale is used to assess stool form: types 1–2 indicate constipation, types 3–4 are normal.
Treatment
1. Clearing the bowel
Hard stool built up in the bowel is first cleared over a few days with a higher dose of laxative.
2. Maintenance laxative
Then a daily laxative is given to keep stools soft. Polyethylene glycol is used most often. The dose is adjusted so the child has a soft, painless stool every day or every other day. Treatment usually lasts at least 2–3 months, often longer, and is tapered gradually.
3. Toilet routine
- sitting on the toilet for 5–10 minutes 15–30 minutes after each meal (using the gastrocolic reflex),
- a support under the feet, knees above the hips,
- no rushing, no punishment, praise for successes.
4. Diet and activity
Enough water, fruits and vegetables, whole grain products, daily physical activity. Too much milk and white flour products can make constipation worse.
When constipation is treated, some of the urinary problems go away without any additional treatment.
When to seek urgent care
If any of the following is present, do not wait for a routine appointment: call the doctor or go to the nearest emergency department.
- Bloating together with severe abdominal pain and vomiting
- Blood in the stool, weight loss
- Fever and pain when urinating
Note for pediatricians and family doctors
Constipation should be actively asked about in every child with a urinary tract infection or reflux; parents often do not mention it. Rome IV criteria and the Bristol stool scale should be used. On ultrasound, a rectal diameter behind the bladder of more than 3 cm suggests constipation. Polyethylene glycol is the first-line treatment; the dose is adjusted until stools are soft.
What happens at the visit?
- Questions about stool frequency, form (Bristol scale), pain, soiling and toilet habits.
- Abdominal examination and, when needed, ultrasound measurement of rectal diameter and residual urine.
- A plan for bowel clean-out, laxative and toilet routine is given.
- The response of urinary problems to constipation treatment is followed.
Frequently asked questions
My child has a bowel movement every day. Can it still be constipation?
Yes. If the bowel does not empty completely, the child may pass small amounts of stool every day while a hard mass stays in the bowel. Sometimes liquid stool leaking into the underwear looks like diarrhea, but it is actually a sign of constipation.
Do laxatives cause dependence?
The osmotic laxatives used in children (for example, polyethylene glycol) do not cause dependence. The most common mistake is stopping treatment too early.
Related topics
Sources
- Santos JD et al. Bladder and bowel dysfunction in children: an update on the diagnosis and treatment. Can Urol Assoc J, 2017.
- Hyams JS et al. Functional disorders: children and adolescents (Rome IV). Gastroenterology, 2016.
This page is for education. Decisions about your child’s treatment are made together with the doctor after an examination.