Colonoscopy unpleasant, but it’s prime for cancer screening

Dear Dr. Roach: I am a 72-year-old male in good health. I’ve had a couple of colonoscopies (the first one found some adenomas), but the required cleansing prep with harsh laxatives has become increasingly difficult for my body to take. I only got halfway into the last prep before becoming so sick that I had to discontinue the cleansing and cancel the colonoscopy.

I’ve been reading about new noninvasive colon cancer detection methods that do not require the harsh prep. Two of them are Cologuard, which analyzes stool samples, and Epi proColon, a blood test. What is your opinion of these?

I realize that they test only for evidence of cancer and that a positive test would call for a colonoscopy, but could they serve as screening tests? Would a negative result mean I could reasonably skip a colonoscopy and its (for me) debilitating prep procedure? B.W.

I recommend colonoscopy as the firstline screening test for colon cancer, as it evaluates the entire colon and allows for a biopsy to be done at the same time. However, colonoscopy is expensive, has risks of side-effects, sometimes can miss small polyps, isn’t available everywhere and isn’t definitively proven to be better than other methods (though most experts think it is, and nearly all choose it for themselves). The preparation is, at best, unpleasant, and some people find it hard.

For people who cannot or will not get a colonoscopy, three options include fecal blood testing, the Cologuard stool DNA test and the Epi proColon blood DNA test. These tests have never been compared with each other, but most authorities believe the Cologuard test and stool blood test are likely more sensitive tests than the blood-based proColon DNA test. However, any of these tests is better than not getting screened at all.

People with a positive test, and people at high risk for colon cancer due to history or medical condition still should have a colonoscopy. Finally, you might ask your gastroenterologist about different preparation options: Some are much better tolerated than others.

Dr. Roach Writes: A recent column about the flu vaccine generated some letters. Some readers wondered whether the questioner may have had a bad reaction to the 1976 swine flu vaccine. I recall that incident, and in medical school, we learned that it wasn’t clear why that vaccine caused more side-effects than other flu vaccines. However, it was a live, attenuated (weakened) flu strain, not the killed flu vaccine that has been the standard now for decades. I certainly have encountered many people who had a bad reaction 40 years ago and who still refuse to get a vaccine now.

Another reader noted that a family member complained of getting “the flu” after a flu shot, but really meant an episode of vomiting or diarrhea. Influenza does not usually have many gastrointestinal symptoms: The term “stomach flu” is a misnomer. There are plenty of viruses that can cause vomiting and diarrhea, but not influenza, which causes sudden onset (my colleague Dr. Fred Pelzman talks about people getting hit with the “flu truck”) of fever, a high degree of fatigue and feeling unwell, headache and sometimes profound muscle aches. Cough, sore throat and nasal discharge show the respiratory nature of this illness.