Allergic proctocolitis: Evaluation and management

Food protein-induced allergic proctocolitis (FPIAP) is a condition that causes rectal bleeding and mucous in stools, which typically presents in healthy infants within the first month of life and improves by 12 months of age. It can present in both breast- and formula-fed infants, with the most common implicated foods being cow's milk and soy protein. Currently, there are no widely accepted diagnostic criteria, but it is considered a clinical diagnosis, with FPIAP symptoms resolving with removal of culprit food(s) and recurrence with food reintroduction. Although the duration of the elimination diet is not well studied, most current guidelines suggest rechallenging with the suspected food after 2-4 weeks because some patients will have spontaneous resolution. Recent studies have shown an increase in the development of immunoglobulin E-mediated food allergies in children with FPIAP, possibly due to prolonged avoidance of the culprit food, which has led to experts debating the risks and benefits of early food reintroduction in FPIAP. This review summarizes our current understanding of the condition and postulates additional mechanistic and outcome investigations needed to better understand the underlying pathophysiology of the condition and the long-term consequences of elimination diets.