During radiotherapy for rectal cancer patients, they should consume more foods that are easy to digest and with high nutritional value, such as fish soup, eggs, protein powder, etc. In addition, probiotics are also crucial for rectal cancer radiotherapy. Starting to take 1-2 kinds of probiotics 1 week before radiotherapy can adjust the intestinal flora and significantly reduce the probability of diarrhea caused by radiotherapy. Common probiotics include lactobacillus, bacillus subtilis, bacillus licheniformis, etc. Choose 1-2 kinds of probiotics and start taking them about 1 week before radiotherapy. If the patient has incomplete intestinal obstruction, it is recommended to eat a less crumbly diet. Less crumbly diet refers to a low-fiber diet, which means that the food fiber content is relatively low and easy to digest. A low-fiber diet is one that contains less fiber and is easier to digest. A low-fiber diet reduces the irritation and obstruction of the gastrointestinal tract caused by food fiber and slows down intestinal peristalsis to reduce the amount of fecal matter. If you have other medical conditions, such as diabetes, you need to consult a specialist and follow the doctor’s advice.