The correct answer is A) Colonoscopy

Colonoscopy is a procedure that involves inserting a flexible tube with a camera into the colon to visualize the mucosa and detect any abnormalities such as polyps, tumors, inflammation, or bleeding. It is indicated for patients with chronic constipation who are older than 50 years or have any red flag features for colorectal malignancy, such as weight loss, blood in stools, anemia, or a family history of colon cancer. This patient meets the age criterion and should undergo colonoscopy to rule out any serious causes of his constipation.

Answer explanations:

• Barium enema is an imaging test that involves injecting a contrast agent (barium sulfate) into the rectum and taking X-rays of the colon. It can show structural abnormalities such as diverticula, strictures, masses, or volvulus. However, it is less sensitive and specific than colonoscopy for detecting colorectal malignancy. Therefore, it is not the preferred test for this patient.


• Thyroid function tests are blood tests that measure the levels of thyroid hormones (T3, T4) and thyroid-stimulating hormone (TSH). They can help diagnose thyroid disorders such as hypothyroidism or hyperthyroidism. Hypothyroidism can cause constipation due to decreased gastrointestinal motility. However, this patient has no other signs or symptoms of hypothyroidism such as fatigue, cold intolerance, dry skin, hair loss, or bradycardia. Therefore, thyroid function tests are not necessary for this patient.


• Stool osmolarity is a test that measures the concentration of solutes in stool water. It can help differentiate between osmotic diarrhea (high stool osmolarity) and secretory diarrhea (low stool osmolarity). However, this test is not useful for evaluating constipation which is defined by infrequent or difficult defecation.


• Dietary modification is a nonpharmacological measure that involves increasing fiber and fluid intake to improve stool consistency and frequency. It may be effective for patients with primary constipation which has no identifiable organic cause. However, this patient has chronic constipation which requires further evaluation before initiating treatment.

(Review PANRE Blueprint Topic: Constipation)

The correct answer is A) Troponin

Acute myocardial infarction (AMI) is a serious medical emergency that requires prompt diagnosis and treatment. Cardiac biomarkers such as troponin, creatinine kinase-MB (CK-MB), and myoglobin are commonly used to diagnose AMI. Among these biomarkers, troponin is the most specific for the diagnosis of AMI. Troponin is a protein found in cardiac muscle cells, and its release into the bloodstream is a specific marker of myocardial injury. Elevated troponin levels are typically seen within 3-4 hours after the onset of symptoms and can remain elevated for up to 10-14 days after an AMI.

Incorrect answer explanations:

• Creatinine kinase (CK) is an enzyme found in various tissues, including skeletal and cardiac muscle. CK-MB is a specific isoform of CK found predominantly in cardiac muscle cells. Elevated levels of CK-MB can be seen in the early stages of AMI, but CK-MB is less specific for the diagnosis of AMI compared to troponin.


• Myoglobin is a protein found in skeletal and cardiac muscle cells. Elevated myoglobin levels can be seen within 1-3 hours after the onset of symptoms, but myoglobin is less specific for the diagnosis of AMI compared to troponin. Elevated myoglobin levels can also be seen in other conditions that cause muscle injury, such as rhabdomyolysis.


• C-reactive protein (CRP) is an acute-phase protein that is elevated in response to