A 41-year-old man presents to his primary care provider after seeing bright red blood in the toilet bowl after his last 2 bowel movements. He reports that he also noticed some blood mixed with his stool. The patient denies abdominal pain or any changes in his stool habits. He notes a weight loss of 8 pounds in the last 2 months with no changes in his diet or exercise habits. His medical history is significant for an episode of pancreatitis 2 years ago for which he was hospitalized for several days. He drinks 2-3 beers on the weekend and he has never smoked. He has no family history of colon cancer. His temperature is 97.6°F (36.4°C), blood pressure is 135/78 mmHg, pulse is 88/min, and respirations are 14/min. On physical exam, his abdomen is soft and non-tender to palpation. Bowel sounds are present, and there is no hepatomegaly. Which of the following is the most appropriate next step in management?
Abdominal CT
Colonoscopy
Ultrasound of abdomen
Barium enema
Colonoscopy
This patient presents with hematochezia and weight loss, which raises concern for colorectal cancer. The most appropriate next step in management is performing a colonoscopy.

The differential diagnosis of hematochezia includes colorectal cancer, inflammatory bowel disease, diverticulosis, and hemorrhoids. The evaluation depends in large part on the age of the patient and whether the patient presents with alarm symptoms such as weight loss, abdominal pain, change in bowel habits, or iron-deficiency anemia. If the patient is over the age of 50, has alarm symptoms, or has a family history of colorectal cancer, the evaluation should begin with a colonoscopy to rule out malignancy. If the patient is between the ages of 40 and 50 and without other red flags, the patient can elect to undergo sigmoidoscopy as a less invasive procedure than colonoscopy. If the patient is under the age of 40 and without alarm symptoms, the workup may begin with an anoscopy to first evaluate for hemorrhoids. Once cancer has been ruled out, additional evaluation for chronic inflammatory diseases such as ulcerative colitis can be conducted.

Church presents evidence regarding the current use of colonoscopy. He discusses how the detection of neoplasia during colonoscopy is suboptimal despite its use as the current screening tool of choice. He recommends understanding which patients are missed and how to better detect neoplasias in these patients.

Incorrect Answers:
Answer A: Abdominal CT might be used to evaluate for metastases if the diagnosis of colorectal cancer is confirmed but it would not be used to diagnose the primary malignancy. A CT scan would be the most appropriate initial step in diagnosis if diffuse metastasis were already suspected such as a presentation of severe weight loss and an enlarged, palpable, and nodular liver.

Answer B: Anoscopy is used for the evaluation of hemorrhoids in a patient < 40 years of age who presents with bright red blood per rectum in the absence of alarm symptoms. It would not be the most appropriate next step for a patient who presents with unexplained weight loss as it cannot be used to diagnose colorectal cancer.

Answer C: Barium enema is sometimes used to screen for colorectal cancer in conjunction with other tests in asymptomatic patients, but it would not be used to diagnose malignancy in a patient with alarm symptoms such as hematochezia and unexpected weight loss.

Answer E: Ultrasound of the abdomen would be effective in diagnosing conditions such as intraperitoneal bleeding and cholecystitis. There is no evidence of abdominal trauma that would suggest intraperitoneal bleeding in this patient. A positive ultrasound with free fluid would be treated with diagnostic laparoscopy.

Bullet Summary:
If a patient is over the age of 50 or has alarm symptoms of weight loss, abdominal pain, change in bowel habits, or iron-deficiency anemia, the patient should undergo a colonoscopy to rule out colorectal cancer.