Prophylaxis of Diarrhea in Adult Cancer Patients Receiving Targeted Cancer Therapy

Inclusion Criteria: * 1\. Patients to receive targeted cancer therapy drugs that have a reported an all grade diarrhea incidence of 50% or higher (e.g., tyrosine kinase inhibitors, cdk inhibitors, anti-EGFR, etc., for treatment of solid tumors. 2\. Patients able to provide written informed consent. 3\. Men and women ≥ 18 years of age. 4\. Pathologically and/or radiologically confirmed diagnosis of solid tumors scheduled to receive targeted cancer therapy. 5\. Patients eligible to receive targeted cancer therapy per NCCN (National Comprehensive Cancer Network) guidelines and/or standard-of-care practice, with or without cycle chemotherapy. 6\. Patient can receive concomitant cycle \[standard\] chemotherapy agents together with their targeted cancer therapy treatment regimens. 7\. ECOG (Eastern Cooperative Oncology Group) performance status 0-2 and expected to survive a 12-week course of targeted therapy with or without chemotherapy 8\. Negative urine pregnancy test at time of informed consent for women of childbearing potential. Exclusion Criteria: * 1\. Patients receiving any type of immunotherapy including but not limited to immune checkpoint inhibitors that inhibit negative regulatory components of immune response such as cytotoxic T-lymphocyte associated antigen 4 (CTLA-4) and the programmed cell death protein-1 and its ligand (PD1/ PDL1) and IL-2 cancer immunotherapy. 2\. Any cancer therapy for which antidiarrheal (antimotility) medications in the prophylaxis setting is mandatory, including but not limited to patients receiving neratinib and irinotecan. 3\. Ongoing irritable bowel syndrome (IBS) or colitis (including but not limited to ulcerative colitis, Crohn's disease, microscopic colitis, etc.). 4\. Ongoing diarrhea and/or diarrheal episodes within the previous 7 days prior to randomization into the study. 5\. Laxative use within 7 days prior to randomization or a history of constipation requiring the use of laxatives for more than ≥ 30 consecutive days. 6\. Inadequate organ function, which may include, but is not limited to, the following laboratory results within 28 days prior to signing consent: Total bilirubin \> upper limit of normal (ULN), AST (SGOT) and ALT (SPGT) \> 2.5 ULN (unless the participant has documented Gilbert's syndrome, hepatocellular carcinoma or hepatic metastases), serum creatinine \> 2.0 mg/dL or 177 μmol/L. 1. NOTE: Investigator discretion will determine continued eligibility after randomization occurs, in the event the liver function test results are greater than (\>) the proposed upper limit of normal. 7\. Use of other investigational drugs within 4 weeks of signed informed consent or foreseen use during the study. 8\. Use of antibiotics within the past 7 days (up to 2 prophylactic doses of antibiotic for procedures, including but not limited to port placement, is permitted) prior to randomization. 9\. Total colectomy and/or any type of gastrointestinal ostomy. 10\. Major abdominal or pelvic surgery within the past 3 months. 11\. Previous (within 1 month) or planned abdominal and/or pelvic radiation. 12\. Fecal incontinence from ongoing radiation-induced diarrhea or constipation 13\. Active systemic infection requiring ongoing intervention, including but not limited to oral and intravenous antibiotics, anti-fungals, anti-parasitics, and anti-viral drugs. 14\. Inability to comply with study requirements as judged by the Investigator. 15\. Pregnant and/or breastfeeding.