Cohort A: Naïve (no irinotecan treatment before) postmenopausal female cancer patients.  Inclusion criteria:  Malignant tumor confirmed by histology or cytology; Postmenopausal women, after bilateral oophorectomy; age > 60 years old, or age < 60 years old with menopause for more than 1 year; Age ≥ 18 years old, ≤ 75 years old; ECOG score of the patient ≤ 2 points; Never been treated with irinotecan; Plan to receive at least 3 rounds of FOLFIRI chemotherapy determined by physicians;  Normal organ functions can meet the requirements for systemic chemotherapy:  Reserve functions of normal bone marrow: absolute neutrophil count (ANC) ≥ 1.5×109/L, PLT ≥ 100×109/L, hemoglobin ≥ 90 g/L; Normal renal functions: serum creatinine ≤ 1.5 mg/dl (133 μmol/L) and/or creatinine clearance ≥ 60 ml/min; Normal hepatic functions: total serum bilirubin level ≤ 1.5 times of the upper limit of normal value (ULN), serum aspartate aminotransferase (AST) & alanine aminotransferase (ALT) ≤ 2.5 × ULN; If abnormal hepatic functions are caused by a potentially malignant tumor, and AST ＆ ALT ≤ 5 × ULN; Patient is willing to participate and cooperate to complete the questions in the case report form; Patient can understand and sign the informed consent form, is well compliant, and can be followed up.  Cohort B: cancer patients who experienced irinotecan -induced diarrhea (grade >2)  Inclusion criteria:  Malignant tumor confirmed by histology or cytology; Age ≥ 18 years old, ≤ 75 years old; ECOG score of the patient ≤ 2 points; Patients who have diarrhea worse than grade 2 due to irinotecan chemotherapy (the last dose of irinotecan is administered within 1 month); Patients who plan to receive 3 rounds of FOLFIRI chemotherapy;  Normal organ functions can meet the requirements for systemic chemotherapy:  Reserve functions of normal bone marrow: absolute neutrophil count (ANC) ≥ 1.5×109/L, PLT ≥ 100×109/L, hemoglobin ≥ 90g/L; Normal renal functions: serum creatinine ≤ 1.5mg/dl (133μmol/L) and/or creatinine clearance ≥ 60ml/min; Normal hepatic functions: total serum bilirubin level ≤ 1.5 times of the upper limit of normal value (ULN), serum aspartate aminotransferase (AST) & alanine aminotransferase (ALT) ≤ 2.5 × ULN; If abnormal hepatic functions are caused by a potentially malignant tumor, and AST ＆ ALT ≤ 5 × ULN; Patient is willing to participate and cooperate to complete the questions in the case report form; Patients can understand and sign the informed consent form, is well compliant, and can be followed up.  Exclusion Criteria:  Patients with diagnosed depression, obsession or/and schizophrenia; Patients with diagnosed inflammatory bowel diseases (including Crohn's disease, ulcerative colitis) Patient with active tuberculosis and other uncontrolled infections; Patient has previously received radiotherapy on the abdominal cavity and pelvic cavity; Pregnant or lactating women; Patient previously had or is now having thromboembolic (blood clotting) events.