Constipation and Down Syndrome
by Len Leshin, MD, FAAP
The direct cause of constipation is not enough water in the stool. This occurs because of the diet not having enough water-retaining elements (fiber) or because the stool is kept in the rectum too long, allowing the colon to reabsorb more water than usual.
If left untreated, constipation can lead to (1) rectal fissures: tears in the rectum leading to bright red blood on the surface of the stool and on the toilet paper, but not mixed in with the stool; (2) impaction; (3) stretching of the rectum leading to the loss of the sensation of the need to have a bowel movement. This last problem can further lead to the weakening of the rectal muscles (sphincters) and cause the child to have bowel movement accidents (in medicalese, "encopresis").
The usual treatment of constipation is dietary: increasing fiber, fruits and vegetables. In bottle-fed babies, the introduction of a stool softener is used, such as corn syrup (Karo), malt barley extract (Maltsupex) or lactulose (Diphulac). Lactulose is also used in children and adults. All of these soften the stool by adding water to the stool. Another way of adding dietary fiber is through products such as Metamucil, Citrucel, or fiber wafers. Increasing the amount of fluids the child drinks is helpful; and in older children, decreasing the amount of constipating foods (milk products, bananas, white rice) may also help.
For babies who are having a hard time passing a stool, the use of glycerin can be helpful. These can be found as solid suppositories or in liquid form (Babylax), and are useful as occasional measure. For severe constipation, your doctor will usually recommend a medicated suppository or enema; please do not use these without consulting your doctor first. Likewise, avoid other laxatives unless your doctor specifically recommends them. The treatment of encopresis is long and involved, and I won't go into that here.
Two special conditions require further mention in children with DS: Hirschsprung disease and hypothyroidism.
Hirschsprung disease is a condition in which a segment of colon directly above the rectum is formed without nerve endings. This condition makes it impossible for that segment to push the stool along into the rectum; the stool backs up just above the rectum and only enters the rectum when enough stool backs up to push the front along (like a train caboose pushing the engine). These babies typically do not pass stool in the first 48 hours of life, and are chronically constipated. Children with DS do have an increased risk of having Hirschsprung disease, and sometimes it can be very difficult for the doctor to tell the difference between Hirschsprung and the normal stooling pattern of a baby with DS. The diagnosis is made by first performing a barium enema on the child, and if that exam is suspicious, confirmed by a rectal biopsy. Treatment is the removal of the segment of colon without the nerve endings (the length is variable from child to child). The traditional treatment was performed in two stages: the first surgery attached the ending of the colon to a specially made opening (colostomy), and then reattachment of the rectum was performed months later. Now, however, many surgeons are removing the involved segment of colon and reattaching the good colon to the rectum in one procedure. This surgery solves the problem of constipation, though children without long segments of colon may have problems with diarrhea and malabsorption for the rest of their lives. Parents of children with Hirschsprung disease may be interested in a parent organization called the Pull-thru Network at www.pullthrunetwork.org/.
Constipation is also one of the signs of hypothyroidism, another condition more common in children with DS. Because the signs and symptoms of hypothyroidism can be well hidden in children with DS, a regular thyroid screening blood test is recommended every one to two years, even if the child is growing well.