Would a gastroenterologist give a urine test?
Yes it is possible that the attending physician may feel the need to order up a urinalysis. It just depends on what the specifics are in regards to the case and the patient. If you are wanting to know whether or not the doctor will order up a urinalysis and then analyze it for drugs, then the answer is no, not unless you give consent. When a urine sample is taken and sent off for analysis, it is not analyzed for everything under the sun, it is only analyzed for the requested testing, and in the case of a gastrointerologist, a urine drug screen would not be ordered unless he or she felt that there may be some type of issue in that area resulting in your GI problems and again, if this was the case, they would have to ask you first, and the results could not be used against you in any way, as you are protected by HIPPA and doctor-patient confidentiality.
