食物过敏的症状呈现非特异性，其中60%的儿童表现为消化系统症状，如便血、腹泻、便秘等，临床上极易误诊和漏诊，导致过度治疗和延误治疗，加重病情，影响患儿生长发育。食物过敏相关消化系统疾病的诊断需遵循3个标准：①有临床症状；②实验室检查（口服食物激发试验）明确过敏原；③食物与症状之间有明确关系。便血在食物蛋白诱导的直肠结肠炎中较为常见，新生儿期需要与感染性腹泻、坏死性小肠结肠炎相鉴别，婴儿期需要与肛裂、肠息肉、肠套叠、梅克尔憩室、肠血管畸形、极早发炎症性肠病、先天免疫缺陷病相关腹泻等鉴别。腹泻在食物蛋白诱导的肠病、食物蛋白诱导的小肠结肠炎综合征中多见，需要和乳糖不耐受、乳糜泻、其他原因引起的腹泻鉴别。食物过敏是否可导致便秘，目前仍存在争论，需要与先天性巨结肠等先天性疾病以及功能性便秘相鉴别。

The symptoms of food allergy present nonspecifically, with 60% of children showing digestive system symptoms such as rectal bleeding, diarrhea, constipation, etc. Clinically, it is highly prone to misdiagnosis and missed diagnosis, leading to over-treatment and delayed treatment, exacerbating the condition and affecting the growth and development of affected children. Three criteria should be followed in the diagnosis of food allergies and associated digestive disorders: (1) clinical symptoms; (2) laboratory testing (oral food challenge) to determine allergens; and (3) a direct correlation between food and symptoms. Rectal bleeding is more common in food protein-induced proctocolitis, and in the neonatal period, it needs to be differentiated from infectious diarrhea and necrotizing enterocolitis. In infancy, it needs to be differentiated from anal fissures, intestinal polyps, intussusception, Meckel’s diverticulum, intestinal vascular malformations, very early-onset inflammatory bowel disease and congenital immunodeficiency disease-related diarrhea. Diarrhea is common in food protein-induced enteropathy and food protein-induced enterocolitis syndrome and needs to be differentiated from lactose intolerance, celiac disease, and diarrhea caused by other reasons. Whether food allergy can cause constipation is still debated, and it needs to be differentiated from congenital megacolon and functional constipation.