Colorectal cancer (CRC) is the third most common cancer globally and the second leading cause of cancer-related deaths; it is characterized by tumors in the lining of the large intestine. Risk factors include smoking, alcohol consumption, sedentary lifestyle, obesity, old age, family history, personal history of CRC, and inflammatory bowel disease, and the prognosis is influenced by an individual's health and cancer spread.

Common signs and symptoms of colorectal cancer (CRC) include changes in bowel habits, bloating, gas pains, fatigue, vomiting, and unexplained weight loss. However, CRC may not show symptoms, which is why screening is recommended for people over age 45.

Colorectal cancer (CRC) is diagnosed using various tests, including colonoscopy or sigmoidoscopy for visual examination and biopsy collection, fecal occult blood tests to detect hidden blood in stool, and DNA stool tests for genetic changes. If CRC is confirmed, additional imaging tests like X-rays and CAT scans are conducted to check for cancer spread.

The main medical treatments for colorectal cancer (CRC) include surgery, which can cure the disease if it is detected early, as well as radiofrequency ablation, cryosurgery, radiation therapy, chemotherapy, and immunotherapy. These treatments can vary in their approaches and target either the cancerous area specifically or affect the entire body.

Some evidence suggests that berberine may reduce the recurrence of colorectal adenomas, and certain herbs from Traditional Chinese Medicine may improve quality of life and treatment response when they are used with chemotherapy, though the evidence is inconsistent. Additionally, probiotics and synbiotics may help reduce postsurgery complications, and vitamin D supplementation has been studied, but the results on its protective effects against colorectal cancer are conflicting.

Diet significantly influences the risk of colorectal cancer (CRC), and prudent dietary patterns like the DASH diet are associated with a 20% reduction in risk. Diets that are high in fiber-rich foods and low in red or processed meat, along with vegetarian and pescatarian diets, are associated with lower CRC risk, whereas high consumption of processed meats and sugars is associated with worse outcomes.

Although exercise is not a direct treatment for colorectal cancer (CRC), engaging in moderate physical activity can enhance survival rates in nonmetastatic cases. Additionally, cognitive interventions, social support groups, and immunonutrition may improve quality of life and post-operative recovery for people with CRC.

The exact cause of colorectal cancer (CRC) is unknown, but it is believed to arise from a combination of lifestyle and genetic factors that lead to uncontrolled intestinal cell division, potentially influenced by oxidative stress. Additionally, Lynch syndrome is a hereditary genetic mutation that greatly increases the risk of developing CRC.