C78.5

Clinical Causes: Spread of primary cancer originating in other organs such as the stomach, pancreas, ovaries, or elsewhere in the abdomen. Metastasis through blood vessels or lymphatic system. Presence of circulating cancer cells that seed new tumor sites in the large intestine and rectum. Advanced stage of a primary cancer that has not been effectively treated or controlled.

Key Symptoms: Changes in bowel habits, including diarrhea, constipation, or a feeling of incomplete evacuation. Persistent abdominal pain or discomfort. Unexplained weight loss and fatigue. Rectal bleeding or blood in stool. Narrowing of the stool or changes in stool consistency. Anemia caused by chronic blood loss. Feeling of fullness or bloating in the abdomen.

Diagnosis Path: Medical history review and physical examination, focusing on abdominal and rectal areas. Imaging tests such as CT scans, MRI, or PET scans to identify tumor locations and assess the extent of spread. Colonoscopy with biopsy to obtain tissue samples for histopathological examination. Blood tests, including tumor markers like CEA (carcinoembryonic antigen), which can support the diagnosis. Additional imaging or endoscopic procedures as needed to evaluate primary cancer sites if unknown.

Treatment Protocols: Systemic therapies such as chemotherapy or targeted biological agents to control tumor growth and reduce symptoms. Radiation therapy, which may be used in specific cases to shrink tumors and relieve pain or other symptoms. Surgical interventions to remove accessible metastatic tumors or relieve obstructions, if feasible. Supportive care, including nutrition management, pain control, and palliative treatments to improve quality of life.