Hemorrhoids and stimulant medications

I have been recently placed on Vyvanse (lisdexamfetamine) for ADHD. I have subsequently noticed that there has been a flare-up of previous hemorrhoid symptoms, perhaps beyond where they had been before. Is this common? I assume that the hypertensive properties of amphetamines may exacerbate a thrombosed hemorrhoid, but I am unsure. Thank you for your response.