5-fu (fluorouracil) Side effects: loss of appetite, nausea, vomiting, stomatitis, abdominal pain, diarrhea, bone marrow suppression, hair loss, bloody stools in severe cases, intestinal perforation Precautions: 350ml-500ml/m2 infusion for 4-8 hours, and formyltetrahydrofolate drip before dosing, drip rate 240ml/h within 42 minutes of starting. If diarrhea occurs more than 5 times a day or bloody diarrhea, inform the doctor and stop the drug if necessary. For continuous drip, deep vein placement is recommended. Capecitabine (Xyroda) Side effects: myelosuppression, nausea, vomiting, diarrhea, hand-foot syndrome (dull palm-foot sensation or chemotherapy-induced erythema of the extremities, a skin toxicity), stomatitis, fatigue, fever. Precautions: The total daily dose is divided into two times in the morning and evening to be swallowed with 200ml of warm water half an hour after meals, so that the drug reaches the intestinal cavity as soon as possible to reduce the gastrointestinal reaction. Take it continuously for 2 weeks and rest for a week as a cycle. Do not touch cold water or metal objects after taking the medicine, put on mask and gloves when going out to avoid laryngeal edema caused by cold stimulation, wear long clothes and pants as much as possible, avoid sunlight, and use sunscreen products for protection. Take good care of your mouth and adjust the dose of medication in case of severe stomatitis. In case of grade 2 diarrhea (4-6 times/day, or nocturnal diarrhea) or above, discontinue the drug immediately and treat the diarrhea as usual until it stops or grade 2, then reintroduce the drug. Irinotecan (Kepto, Ally) Side effects: Gastrointestinal reactions: delayed diarrhea (occurring 24h after dosing), acute cholinergic syndrome: early onset diarrhea and other symptoms such as abdominal pain, conjunctivitis, rhinitis, hypotension, vasodilation, sweating, chills, general malaise, dizziness, visual disturbances, narrow pupils, increased lacrimation and salivation within the first 24 hours after dosing. Leukocytopenia, thrombocytopenia, anemia and bone marrow suppression combined with infection. Precautions: Use immediately after dilution of this drug for 30-90 minutes in a sedative drip. Patients avoid foods and beverages that may cause diarrhea during the use of the drug, and drugs that increase intestinal motility are prohibited. After the use of Ally, it is necessary to always have Emmenthal around. The treatment must be started immediately (within 2 hours) after 24 hours of administration in case of loose stools or abnormal peristalsis, by taking 2# orally for the first time and then 1# orally every 2 hours for at least 12 hours until the diarrhea stops for 12 hours, but not for more than 48 hours in total and not for prophylactic use. In combination with folinic acid and 5-fu, this drug should be used first. Oxaliplatin (Loxadine, ACE) Side effects: neurotoxicity, gastrointestinal reactions, diarrhea, hematologic toxicity Precautions: This drug must be administered before fluorouracil, 2-6 hours by intravenous infusion, and should not be used with alkaline drugs or solutions or chlorinated substances, including any concentration of sodium chloride. Degrades on contact with aluminum; use oxaliplatin in aluminum containers only. Hypothermia can cause upper respiratory tract spasms and peripheral neurotoxic reactions; keep warm. Hands and feet should not be exposed to cold objects, including cold water and cold air, for one week after the end of dosing. Keep warm to avoid upper respiratory tract spasms and sensory disturbances due to cold stimulation.