Polyethylene glycol electrolyte (PEG-3350) solution is usually used for bowel emptying before colonoscopy in adults. It has also been reported to be safe in children.It is thought that bowel irrigation with this solution can be a useful treatment alternative for poisoning with slow releasing drugs, swallowed packaged substances, enteric coated drugs, drugs not binding to charcoal, and heavy metals in children. Due to high molecular weight of PEG-3350, its absorption from the intestinal mucosa is very low (0.2%).Therefore, it is less likely to have side effects. A three-year-old girl bit and ate one-third of an alkali battery and was brought to our pediatric emergency unit. Vital signs and results of physical examination and laboratory investigations were normal. Irrigation of the bowels with PEG-3350 solution given orally at a rate of 20 mL/kg/h was initiated. Upon excretion of feces of normal appearance in the sixth hour, irrigation was continued. Since rashes and itching started throughout her body in the thirtieth hour after administration of 9 L PEG-3350, the irrigation was discontinued and the patient was administered antihistamines. Rashes and itching regressed within one hour of its discontinuation. This suggested that they were due to the irrigation solution.There are five adult cases of allergic reactions to PEG-3350 reported in the literature. The case presented is the first pediatric patient developing allergic reaction to PEG-3350.