Infant Diarrhea Causes

Infant diarrhea is characterized by a watery stools and an increase in both volume and frequency of bowel movements, says the University of Maryland Medical Center (UMM). explains that true diarrhea is identified when an infant has a sudden change in the frequency and consistency of bowel movements. A short bout of diarrhea may be nothing to worry about, but persistent diarrhea can lead to dehydration. There are several potential causes of infant diarrhea.

Viral Infection

There are several common viruses that can cause infant diarrhea. says these include rotovirus, adenovirus, calcivirus, astrovirus and viral influenza. All of these viruses lead to the same basic symptoms including cramping with the diarrhea, fever, abdominal pain, chills and achiness. Some viruses may also cause vomiting. Treatment of this type of infant diarrhea focuses on rehydrating the infant and comforting him. Viral diarrhea is extremely contagious and can spread from one infected person to another. Poorly handling an infant’s dirty diapers can cause the virus to be spread to caregivers and even to other children. This is also the potential source of the original infant infection, especially when the infant begins putting his hands into his mouth and is exposed to different people daily such as in a day care.

Bacterial Infection

Like viruses, there are several bacterial sources of infant diarrhea. identifies the most common including salmonella, shigella, staphylococcus, campylobacter or E. coli. Symptoms of bacterial diarrhea include cramps, blood in the stool and a fever with the diarrhea. These infections can be caused by contaminated foods or from ingesting fecal matter of an infected person. Infant’s who are strictly formula-fed or breast-fed are likely to get the bacteria from putting a contaminated object into the mouth. Poorly stored infant cereals or formulas can develop bacteria if they are left at room temperature too long or kept in the refrigerator for longer than recommended by the product label. A bacterial infection may be treated with antibiotics and rehydration of the infant.

Ear Infection

An ear infection can cause an infant to have a short bout of diarrhea, lasting about a day. In addition to the diarrhea, the infant may be overly fussy, especially at night. When lying down, the pain in the ears can be exacerbated by the fluids resting against the inner ear components. A trip to the doctor will help reveal the source of the infant’s overall discomfort.


Parasites can cause several intestinal symptoms in addition to diarrhea. These include gas, bloating and greasy stools, says A microscopic parasite is most often spread in a group setting such as a day care or hospital. Some parasites can come from the fecal matter of household pets.


Some antibiotics prescribed for other ailments may cause diarrhea. One reason for this is that the antibiotics kill off good bacteria in the intestines, which help regulate the bowels. If diarrhea is a potential side effect of the antibiotic, it is likely that it will be listed on the product label. A pharmacist or doctor can clarify this.

Fruit Juice explains that providing too much juice to an infant, especially those containing sorbitol or high levels of fructose, can upset the baby’s stomach. Infants should not receive juice before the sixth month of life, says the American Academy of Pediatrics. Skipping juice for several weeks can remedy the diarrhea. It is also possible that an infant may not tolerate some more acidic juices.

Food Sensitivity

A sensitivity, intolerance or allergy to particular foods may lead to a brief bout of diarrhea. It may be difficult to identify the cause of the diarrhea if proper methods of food introduction have not been followed. It is recommended that new foods and drinks be introduced slowly, with at least four days in between each new food. This allows caregivers to identify any food sensitivities.

About this Author

Sarah Irene holds a master’s degree in clinical psychology. Having written stacks of research articles dating back to 2000 and consulted in a number of settings, she is able to be a resource for a vast range of topics. She has been a psychology instructor since 2006 and has had her work published by LIVESTRONG Health and ParentDish.