My uncle is in the US on B1/B2 Multiple VISA and was granted 6 months stay at the port of entry. He also holds a multiple entry visa to Canada obtained from overseas. My uncle wishes to visit Canada briefly but he fears that upon returning to the US, his 6 months of stay in the US will be revoked and then he will be under the mercy of the US Immigration officer to grant him another period of stay that could be as short as one month if any. Are these ligitmate fears or upon returning back to the US he will continue his 6 months of stay regardless? Your feedback is much appreciated. Thanks.