CANCER of the colon and rectum is the leading cause of death from cancer in the United States. Early diagnosis is particularly important for lesions of this portion of the gastrointestinal tract if optimum cure rates are to be achieved. Carcinomas of the right side of the colon are thought of as being relatively silent lesions producing nonspecific symptoms such as fatigue, weakness, and vague lower abdominal pain. Contrary to this, left-sided carcinomas are frequently more dramatic producing changes in bowel habits, bloody stools, and obstruction. Most important, up to 50% of the latter lesions are palpable on rectal examination.1
When carcinoma of the colon causes intestinal obstruction, the lesion is most frequently left-sided in a ratio of 7 to 1.2 Because of the predominance of left-sided colon carcinomas causing obstruction, physicians frequently fail to consider that right colon carcinoma may cause intestinal obstruction. It is the purpose