Dear Sir/ Madam Thanks for your query. Merely undergoing a colonoscopy is not good enough a reason for lower blood pressure. Although blood pressure changes, especially it decreases in summers or when you drink less water for long duration or when you are out of a long term stress. Since your real life doctor is suggesting a cut in medicines, you should follow his advise and remain under monitoring. If BP goes up again, he may increase the dose. That seems logical. Sincerely Sukhvinder