Can taking 1000 mg daily of an orange chewable vitamin c cause occult blood in a color guard test?

No. Vitamin C would not cause a false positive Cologuard test. If you had a positive test, it is imperative that you consider getting colonoscopy.

The orange color should not affect the colon test BUT if you take it regularly (usually not a bad thing) & it causes some stomach inflammation with bits of bleeding there is a possibility it could lead to a positive test. Your Dr MIGHT consider repeating your test in 4-6 weeks while off of vitamin C but may also want you to consider colonoscopy 4-6