What Is Causing My Child's Diarrhea?

     Diarrhea is a common problem in children and it is helpful for parents to have some general rules of thumb that can identify what might be causing the diarrhea. Doctors divide diarrhea into three groups: acute (which lasts for 1-2 weeks), persistent (which lasts for 2weeks to one month) and chronic (which lasts for over a month). Of course, when your child has diarrhea, it is impossible to know how long the diarrhea is going to last unless you have a crystal ball but the categories can still be helpful.

     Viral infection causes the most common form of diarrhea: acute diarrhea. This often begins with fever and vomiting for 24 -48 hours and then the child has diarrhea for a week or two. At first, the stools may be very frequent and the child may feel very ill. The greatest risk with this form of diarrhea is dehydration and the only treatment is to give lots of water and electrolytes to keep the child hydrated. This means small sips frequently of a rehydrating solution: a mixture of water, sugar and salts. After a few days the frequency of the stools will slow down, but they may stay liquid for 2 weeks. If the symptoms are more dramatic or there is blood in the stool, a bacteria such as E. coli could be the cause of the diarrhea and the child’s caregiver should be consulted.

     Persistent diarrhea usually doesn’t come on as dramatically as acute diarrhea. The child may have cramping and a few loose stools but continues to have them longer than 2 weeks. This type of diarrhea is most commonly caused by an infection with a small organism called a protozoan parasite. The most common ones are Giardia and Cryptosporidium. These parasites are usually in water and the child becomes infected by drinking the water. Giardia is common in small, natural sources of water such as streams and ponds and wells. Cryptosporidium can survive up to 10 days in chlorinated water, so it is commonly found in swimming pools. Cryptosporidium is also sometimes acquired in petting zoos (so, good hand-washing should always be the rule after being in a petting zoo). With these infections, the child is not terribly sick, but he may have cramping. The stools are not frequent, but they are persistently liquid. Protozoan parasite infections can be difficult to diagnose. Even though there may be many eggs in the child’s stools, they may be difficult to find in a stool sample. There are medications that can kill the parasite and treat the diarrhea.

     If the child’s diarrhea lasts for longer than a month, or if it seems to come and go for longer than a month, it is chronic diarrhea. Strangely enough, one of the most common causes of chronic diarrhea is constipation. The child has recurrent abdominal cramps – especially after meals. Some stools are large and hard but others are explosive and liquid. A simple X-ray of the abdomen will show whether too much stool is the cause of the problem. Other causes of chronic diarrhea are: gluten intolerance, food (especially milk) allergy, lactose intolerance and any of the many forms of inflammatory bowel disease. This kind of diarrhea needs a full work-up by the child’s caregiver.