For malignant tumors and colorectal cancer, the suggested dietary recommendations after surgery include, first and foremost, consuming nutritious foods to replenish the nutrients depleted by the surgery and the tumor. It is advisable to eat more nutritional items. Secondly, after surgery for rectal cancer, it's important to avoid hard-to-digest and gas-producing foods such as beans, milk, and eggs. Thirdly, it is recommended to consume easily digestible items like soups and nutritious porridge. The fourth recommendation is to avoid spicy and irritating foods, and abstain from alcohol and smoking.