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.

1.Duma N, Santana-Davila R, Molina JR. Non-small cell lung cancer: epidemiology, screening, diagnosis, and treatment[J]. Mayo Clin Proc, 2019, 94(8): 1623-1640. DOI: 10.1016/j.mayocp.2019.01.013.

2.Ettinger DS, Wood DE, Aisner DL, et al. NCCN Guidelines® insights: non-small cell lung cancer, version 2.2023[J]. J Natl Compr Canc Netw, 2023, 21(4): 340-350. DOI: 10.6004/jnccn.2023.0020.

3.Feng Y, Tao Y, Chen H, et al. Efficacy and safety of immune checkpoint inhibitor rechallenge in non-small cell lung cancer: a systematic review and meta-analysis[J]. Thorac Cancer, 2023, 14(25): 2536-2547. DOI: 10.1111/1759-7714.15063.

4.Berner F, Flatz L. Autoimmunity in immune checkpoint inhibitor-induced immune-related adverse events: a focus on autoimmune skin toxicity and pneumonitis[J]. Immunol Rev, 2023 , 318(1): 37-50. DOI: 10.1111/imr.13258.

5.Li X, Lei Y, Liu J, et al. Case report: a successful treatment with immune checkpoint inhibitors was associated with severe dermatologic toxicities in a patient with double primary malignancies[J]. Discov Oncol, 2023, 14(1): 146. DOI: 10.1007/s12672-023-00749-5.

6.Duraisamy P, Panicker VV, Jose WM. Characterization and prognostic significance of cutaneous immune-related adverse events in Indian patients on immune checkpoint inhibitor therapy[J]. Dermatol Pract Concept, 2023, 13(3): e2023127. DOI: 10.5826/dpc.1303a127.

7.Khandakar B, Srivastava A. Immune checkpoint inhibitor therapy associated enteritis mimicking celiac disease[J]. Gastroenterol Hepatol Bed Bench, 2023, 16(2): 240-244. DOI: 10.22037/ghfbb.v16i2.2855.

8.Xie XH, Shen PX, Wu JH, et al. Recurrent pleural effusion as a rare manifestation after prolonged PD1 inhibitor (camrelizumab)-based immunotherapy: a case report[J]. Hum Vaccin Immunother, 2023, 19(2): 2240689. DOI: 10.1080/21645515.2023.2240689.

9.Hakozaki T, Richard C, Elkrief A, et al. The gut microbiome associates with immune checkpoint Inhibition outcomes in patients with advanced non-small cell lung cancer[J]. Cancer Immunol Res, 2020, 8(10): 1243-1250. DOI: 10.1158/2326-6066.Cir-20-0196.

10.Naranjo CA, Busto U, Sellers EM, et al. A method for estimating the probability of adverse drug reactions[J]. Clin Pharmacol Ther, 1981, 30(2): 239-245. DOI: 10.1038/clpt.1981.154.

11.白黎, 王珂. 免疫检查点抑制剂导致免疫相关不良反应的研究进展[J]. 长春中医药大学学报, 2023, 39(2): 229-236. [Bai L, Wang K. Progress of immune checkpoint inhibitors in causing immune-related adverse reactions[J]. Journal of Changchun University of Traditional Chinese Medicine, 2023, 39(2): 229-236.] DOI: 229-36.10.13463/j.cnki.cczyy.2023.02.025.

12.Abu Sbeih H, Wang Y. Management considerations for immune checkpoint inhibitor-induced enterocolitis based on management of inflammatory bowel disease[J]. Inflamm Bowel Dis, 2020, 26(5): 662-668. DOI: 10.1093/ibd/izz212.

13.Garcia-Neuer M, Marmarelis ME, Jangi SR, et al. Diagnostic comparison of CT scans and colonoscopy for immune-related colitis in ipilimumab-treated advanced melanoma patients[J]. Cancer Immunol Res, 2017, 5(4): 286-291. DOI: 10.1158/2326-6066.Cir-16-0302.

14.Kim KW, Ramaiya NH, Krajewski KM, et al. Ipilimumab-associated colitis: CT findings[J]. AJR Am J Roentgenol, 2013, 200(5): W468-474. DOI: 10.2214/ajr.12.9751.

15.Soularue E, Lepage P, Colombel JF, et al. Enterocolitis due to immune checkpoint inhibitors: a systematic review[J]. Gut, 2018, 67(11): 2056-2067. DOI: 10.1136/gutjnl-2018-316948.

16.Chen JH, Pezhouh MK, Lauwers GY, et al. Histopathologic features of colitis due to immunotherapy with anti-PD-1 antibodies[J]. Am J Surg Pathol, 2017, 41(5): 643-654. DOI: 10.1097/pas.0000000000000829.

17.Araujo DV, Muniz TP, Yang A, et al. Real world outcomes and hepatotoxicity of infliximab in the treatment of steroid-refractory immune-related adverse events[J]. Curr Oncol, 2021, 28(3): 2173-2179. DOI: 10.3390/curroncol28030201.

18.Menzies AM, Johnson DB, Ramanujam S, et al. Anti-PD-1 therapy in patients with advanced melanoma and preexisting autoimmune disorders or major toxicity with ipilimumab[J]. Ann Oncol, 2017, 28(2): 368-376. DOI: 10.1093/annonc/mdw443.

19.Johnson DB, Sullivan RJ, Ott PA, et al. Ipilimumab therapy in patients with advanced melanoma and preexisting autoimmune disorders[J]. JAMA Oncol, 2016, 2(2): 234-240. DOI: 10.1001/jamaoncol.2015.4368.

20.The U.S. National Cancer Institute.Common terminology criteria for adverse events (CTCAE) v5.0.[EB/OL].（2017-11-27）[2023-08-03]. http://ctep.cancer.gov/protocolDevelopment/electronic_applications/ctc.htm.

21.中国临床肿瘤学会指南工作委员会, 编. 免疫检查点抑制剂相关的毒性管理指南（2021版）[M]. 北京: 人民卫生出版社, 2021: 60-63.

22.Thompson JA, Schneider BJ, Brahmer J, et al. NCCN Guidelines insights: management of immunotherapy-related toxicities, version 1.2020[J]. J Natl Compr Canc Netw, 2020, 18(3): 230-241. DOI: 10.6004/jnccn.2020.0012.

23.Thompson JA, Schneider BJ, Brahmer J, et al. Management of immunotherapy-related toxicities, version 1.2022, NCCN clinical practice guidelines in oncology[J]. J Natl Compr Canc Netw, 2022, 20(4): 387-405. DOI: 10.6004/jnccn.2022.0020.

24.Dougan M. Gastrointestinal and hepatic complications of immunotherapy: current management and future perspectives[J]. Curr Gastroenterol Rep, 2020, 22(4): 15. DOI: 10.1007/s11894-020-0752-z.

25.Cho JH, Suh S. Glucocorticoid-induced hyperglycemia: a neglected problem[J]. Endocrinol Metab (Seoul), 2024, 39(2): 222-238. DOI: 10.3803/EnM.2024.1951.