A 68-year-old patient with non-small cell lung squamous carcinoma who received 6 cycles of sintilimab combination chemotherapy and sintilimab 200 mg,ivd,monotherapy developed severe diarrhea,abdominal pain,blood in the stool and other discomforts,and ultrasound and colonoscopy demonstrated extensive congestion and inflammation in the intestinal tract,and the pathologic biopsy was comprehensively considered to be an acute immune enteritis.Immunotherapy was suspended,adequate glucocorticoids and symptomatic treatment were given,and the patient's diarrhea and blood in stool improved after 2 days,and the symptoms were relieved and returned to normal after 6 days.The association between the patient's immune enteritis and sintilimab was assessed as probably relerant.This article reviews the literature on the case of immune-associated enteritis caused by sintilimab,describes how to use experimental methods and enteroscopy to detect the pathological changes in the clinic;and combines them with the clinical manifestations of diarrhea and blood in the stools to make the diagnosis and differentiation;and then refers to the guideline grading for timely management;and discusses the case to improve the clinicians'ability to recognize and deal with the relevant scenarios.