Bowel obstruction in children is not uncommon and can affect the small or large bowel. There can be minor and major malformations of the gut, which declare themselves soon after birth. Here are some of the more common conditions.
Hypertrophic Pyloric Stenosis
Here the baby usually feeds well until the 4th to 6th week and then suddenly starts vomiting after every feeding. Within a short period of time there is projectile vomiting where the milk is vomited several feet out. This is due to a thickened (=hypertrophic) outlet from the stomach. The baby has abdominal pain in the epigastric area and eventually no food will pass leading to severe dehydration quickly. These infants need emergency attention at the hospital with a referral to a pediatrician and pediatric surgeon. A relatively small incision will be made and the hypertrophic muscle divided without entering into the lumen of the pylorus. These infants do very well following this procedure and thrive after that.
Meconium Plug Syndrome
Meconium is the name for the first stool of a baby. It looks dark green, sometimes almost black and is of a tarry, pasty consistence. In babies with cystic fibrosis the meconium that is formed in the gut is more tenacious, stickier and can get stuck in the terminal ileum before it would get into the colon. This meconium plug is the reason for a dangerous syndrome where a bowel obstruction develops proximally to the meconium plug, but the colon distally is empty and normal. The diapers do not show bowel movements, but the small bowel shows dilated bowel loops, which very quickly leads to fluid disbalances in the blood stream. A pediatrician needs to stabilize the baby’s condition and diagnose the bowel obstruction due to the meconium plug syndrome. Next a pediatric surgeon needs to get involved to see whether the plug will resolve with diluted contrast medium enemas or whether it will need operative intervention.
Megacolon
In this disease that is also known as Hischsprung’s disease there is a segment of colon with a congenitally absent nerve plexus (=aganglionic colon segment), which is usually located in the distal colon. It may go unnoticed first, but as time progresses, the infant becomes more and more constipated and at the same time there is bowel distension in the left lower and mid abdomen as the stool is building up in front of the section that has no peristalsis. Conceptually it is almost like a mini-ileus. The risk is that a megacolon develops, which in time becomes filled with toxic substances and infection (=”toxic megacolon”). The infant or older child may fail to thrive, have no appetite, have recurrent left abdominal pain and bowel distension with visible peristalsis (= you can see a bowel loop move like a snake underneath the skin). This disease needs urgent attention by a pediatric surgeon.
The surgeon will either do a one-stage or two-staged procedure. In the one-stage procedure (usually when there is no toxic megacolon present) the surgeon removes the defective portion of the colon and repairs the normal colon with an end-to-end anastomosis. With a two-staged procedure the first stage is to do a colostomy(=create an opening in the skin to which the proximal colon is connected). This reestablishes normal emptying of the bowel contents from the healthy proximal colon. The colostomy is covered with a bag that is changed regularly. At a future date when the megacolon has settled down the resection of the defective part (with Hirschsprung’s disease) is removed and an end -to-end anastomosis is done. This way an high risk surgery is broken down into two stages and the patient has a much better survival chance. When all is done, the infant grows normally and has a normal life expectancy.
Anal Atresia
Occasionally a baby is born where the anal opening is missing. This is called anal atresia. It is a developmental anomaly where a membrane that was there in embryonic life has not disappeared. This is an emergency and has to be taken care of right away. If it is missed on day 1, it will develop into acute bowel obstruction with abdominal distension, pain and vomiting on day 2. Usually the physician picks up the problem with the initial examination of the newborn right after delivery and then arranges a referral to a pediatric surgeon immediately. If it is a small problem, a minor surgery opens the anal canal. However, often there are fistulas and other anomalies of the lower urinary tract and of the vagina including pathological fistulas from these structures to the rectum or the skin. Occasionally the surgeon will decide that a preliminary colostomy is done to relieve the obstruction. At a future date when the child has grown and the tissue structures are bigger, the definite corrective surgery can be done with less fear of excessive scarring.
Bowel Atresia
Obstructive membranes can occur in other parts of the gut, most commonly in the ileum(the last part of the small bowel), followed by the duodenum, the jejunum(=upper part of small bowel) and the colon. Symptoms are dictated by the location of the atresia. In other words a high atresia(duodenum or jejunum) leads to regurgitation and vomiting much earlier and might even be mistaken for a hypertrophic pyloric stenosis. With an atresia of the ileum the symptoms are that of small bowel obstruction. Finally, with colonic atresia the symptoms are those of large bowel obstruction with less violent symptoms, less fluid problems and vomiting at a later time than with small bowel obstruction.
References:
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