Dietary protein induced proctocolitis (DPIPC) can be considered as a cause of rectal bleeding or blood streaked stool in otherwise healthy-looking infants in the first several months of life. Failure to appreciate this entity may lead to inappropriate diagnostic or therapeutic intervention. This study aimed to ascertain the clinical features, treatment and prognosis of DPIPC.

We reviewed 13 infants retrospectively, presented with bloody stool in early infancy. They were diagnosed as DPIPC clinically in Pusan National University Hospital from May 2002 to June 2004.

Seven males and six females were included. The mean age at onset of bleeding was 96.8±58.8 days. The mean frequency of hematochezia was 2.6±2.5 times a day. Duration from onset of symptom to diagnosis was 35.5±55.0 days and duration from onset of symptom to resolution of bleeding was 58.7±67.0 days. Nine (69.2%) were exclusively breast-fed infants and two (15.4%) were formula-fed infants. All but one infant did not have family history of other allergic diseases. A dietary history of ingestion of cow's milk, nut or shellfish was present in three mothers. Peripheral eosinophil count was normal to slightly elevated (total WBC count 10,555±3,145/mm³, relative eosinophil count 6.3±3.0%, absolute eosinophil count 659.0±532.2/mm³). Sigmoidoscopy revealed lymphonodular hyperplasia with surrounding hemorrhagic spots in the rectosigmoid colon in 6 infants. Histopathologic finding of colonic biopsies in 5 infants showed chronic inflammation with lymphoid follicular hyperplasia (5 infants), crypt abscess (3 infants), or mild infiltration of eosinophils (less than 20/high power field) in the lamina propria. Spontaneous resolution of rectal bleeding occurred in all infants without dietary change or medicine.

Most infants with DPIPC experience a very benign course and have spontaneous resolution of rectal bleeding without changes in the mother's diet. In the case of strong evidence for DPIPC we suggest deferring further invasive investigation and continuing breast feeding.