CaseAn eleven-year old male patient was referred to another hospital with complaints of alternation in consciousness and stupor which developed in one-two hours. Afterwards, bilious vomiting was observed for 5-6 times; fever, diarrhea or seizures were not observed. Laboratory tests revealed mild reduction in sodium (133 mmol/L) and complete blood count, serum biochemical values, blood gases, ammonia and lactate values were found to be normal. Electrocardiographic examination, echocardiographic examination and cranial magnetic resonance imaging (MRI) were found to be normal. The pediatric patient who had a picture of encephalopathy and whose consciousness deteriorated in 24 hours was internalized in our pediatric intensive care unit. It was learned that he had upper respiratory tract infection about two weeks ago and recovered without using medication. No drug usage or trauma was described before the complaints. No additional pathology was reported in his personal history and familial history. His vaccinations had been administered in accordance with the immunization schedule. It was stated that he had age-appropriate neuromotor development.Physical examination revealed that the patient had a Glaskow coma score of 10, stupor and confusion. His respiratory rate was increased at the time of hospitalization (60/min). His body temperature, blood pressure and apical heart beat were found to be normal. He had no sign of dehydratation. Petechia or ecchymosis was not observed. Examination of the respiratory and cardiovascular system was found to be normal. On abdominal examination, the abdomen was easy, intestinal sounds were reduced, a sense of fullness was found below the liver and a mass extending from the right middle area to the left upper quadrant was palpable. Abdominal tenderness or rebound was not found. On neurological examination, withdrawal response to stimuli was present despite central hypotony. The pupillae were isocoric and light reflex was positive. His reflexes were found to be normal. Meningeal irritation sign or pathological reflex was not found. Pathological lymphadenomegaly was not found. Strawberry jam-like bloody, juicy feces was observed with rectal examination.