Endoscopic insights into digestive-related adverse effects of immune checkpoint inhibitors: A narrative review

Table 2 Classification of lower gastrointestinal symptom severity according to the Common Terminology Criteria for Adverse Events

Condition	Grade 1	Grade 2	Grade 3	Grade 4	Grade 5
Anal pain	Mild pain	Moderate pain; Limiting instrumental ADL	Severe pain; Limiting self-care ADL
Colitis	Asymptomatic; Clinical or diagnostic observations only; Intervention not indicated	Abdominal pain; Mucus or blood in stool	Severe abdominal pain; Peritoneal signs	Life-threatening consequences; Urgent intervention indicated	Death
Diarrhea	Increase of < 4 stools per day over baseline; Mild increase in ostomy output compared to baseline	Increase of 4-6 stools per day over baseline; Moderate increase in ostomy output; Limiting instrumental ADL	Increase of ≥ 7 stools per day over baseline; Hospitalization indicated; Severe increase in ostomy output; Limiting self-care ADL	Life-threatening consequences; Urgent intervention indicated	Death
Upper GI hemorrhage	Mild symptoms; Intervention not indicated	Moderate symptoms; Intervention indicated	Transfusion indicated; Invasive intervention indicated; Hospitalization	Life-threatening consequences; Urgent intervention indicated	Death

GI: Gastrointestinal; ADL: Activities of daily living.