ICD-10 guidelines, section IV.H explains:
"Do not code diagnoses documented as "probable", "suspected," "questionable," "rule out" or "working diagnosis" or other similar terms indicating uncertainty. Rather, code the condition(s) to the highest degree of certainty for that encounter/visit, such as symptoms, signs , abnormal tests results, or other reason for the visit."
When a diagnosis is uncertain, and you have the opportunity to query the provider; generally it's a good idea to do so. In this example where the provider lists two diagnoses and adds "or", then that adds a significant degree of uncertainty. I would check with the provider to get clarification, or simply not code it without documentation support. Even with clarification, I would still be hesitant to code either of the codes based on the documentation, unless the provider provides a timely addendum (outpatient settings only).