What might be causing long-term diarrhea for my 18-month-old?
If she is gaining weight and growing normally, here are several likely candidates for the cause of your problem.
Five months ago is about the time you started her on cow's milk. If so, eliminating milk may solve the problem. If you use a milk substitute, however, be sure it is fortified with Vitamin D and calcium.
Fruit juice can cause loose stools. The American Academy of Pediatrics recommends that we limit the amount of juice that we give children over 6 months to a maximum of 6 ounces per day.
Antibiotics can cause diarrhea, but the problem usually disappears when the prescription is finished. Frequent antibiotic courses can lead to a serious intestinal problem, but that tends to cause bloody diarrhea with severe cramping.
A parasite called giardia lamblia can cause frequent, loose stools that come and go. This infection is particularly common in children who are in group care. A lot of gas and some foamy mucus are characteristic but do not always occur. A stool test can uncover this organism.
There are some other possibilities, such as infections and sensitivities to wheat and other foods, which are less common and more difficult to diagnose. If your pediatrician is dismissing this but you are worried, ask about referral to a specialist. - Loraine Stern, M.D.