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If I Repeat The FOBT Test, Can I Get A
Posted on
Thu, 2 Jan 2020
Medically reviewed by
Ask A Doctor - 24x7 Medical Review Team
Thu, 2 Jan 2020
Answered on
Last reviewed on
Question : If I repeat the FOBT test, can I get a more accurate result to say whether or not I have an early colon cancer?
Brief Answer:
colonoscopy ios a sure shot test.
Detailed Answer:
Hello and thanks for choosing "Ask a Doctor" service for your query,
Have seen your query,
Occult blood test is just a basic test and can be positive due to number of reasons.
I would suggest you to go for a planned colonoscopy to rule out colon cancer.
It is the most accurate test and can be done by any gastroenterologist.
They are going to put a small camera on a smooth tube and complete colon could be visualized with it.
You could consult your gastro for the same.
Hope i was helpful,
Follow ups are welcome,
Thank you!
colonoscopy ios a sure shot test.
Detailed Answer:
Hello and thanks for choosing "Ask a Doctor" service for your query,
Have seen your query,
Occult blood test is just a basic test and can be positive due to number of reasons.
I would suggest you to go for a planned colonoscopy to rule out colon cancer.
It is the most accurate test and can be done by any gastroenterologist.
They are going to put a small camera on a smooth tube and complete colon could be visualized with it.
You could consult your gastro for the same.
Hope i was helpful,
Follow ups are welcome,
Thank you!
Above answer was peer-reviewed by :
Dr. Yogesh D
Hello Dr. XXXXXXX Yes, I realize that colonoscopy is the best test & I will be getting one in about 5 days.
I want to better understand test specificity & sensitivity. I want to know if repeat testing improves either number. This is more of a general medical statistics question, I suppose... because it applies to all medical tests.
Thank you
I want to better understand test specificity & sensitivity. I want to know if repeat testing improves either number. This is more of a general medical statistics question, I suppose... because it applies to all medical tests.
Thank you
Brief Answer:
Follow up answer.
Detailed Answer:
Hi there,
Apart from FOBT the other two tests available to screen colon cancer are The fecal immunochemical test (FIT) and stool DNA test (sDNA).
As per standard books,
For FIT the reported sensitivities has a range from 25% to 98% for CRC and specificities usually exceeding 90%.
So you can see there is a very long range.
For stool DNA test sensitivity range is in between 48.0% to 77.8%, respectively, while the specificities were 97.0% to 92.7%.
So you can see that though specificity is high yet sensitivity of both tests have a wide range.
Lastly if you are getting a colonoscopy done in 5 days there is no point in getting these low sensitivity high cost tests done.
Repeating FOBT won't show any thing else if its showing blood in stool thats it.
Please feel free to follow up and ask any query related to question if i failed to understand what you were asking.
Thank you.
Follow up answer.
Detailed Answer:
Hi there,
Apart from FOBT the other two tests available to screen colon cancer are The fecal immunochemical test (FIT) and stool DNA test (sDNA).
As per standard books,
For FIT the reported sensitivities has a range from 25% to 98% for CRC and specificities usually exceeding 90%.
So you can see there is a very long range.
For stool DNA test sensitivity range is in between 48.0% to 77.8%, respectively, while the specificities were 97.0% to 92.7%.
So you can see that though specificity is high yet sensitivity of both tests have a wide range.
Lastly if you are getting a colonoscopy done in 5 days there is no point in getting these low sensitivity high cost tests done.
Repeating FOBT won't show any thing else if its showing blood in stool thats it.
Please feel free to follow up and ask any query related to question if i failed to understand what you were asking.
Thank you.
Above answer was peer-reviewed by :
Dr. Yogesh D
Answered by
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