Hello!
Welcome and thank you for asking on HCM!
I understand your concern and would explain that dark stools are very concerning about a gastro intestinal hemorrhage (related to
diverticulitis or any other disorders).
Your past medical history for diverticulitis and
colon cancer could be related to these symptoms.
But a common viral gastro enteritis as the cause of this symptomatology can not be excluded.
I recommend consulting with your gastroenterologist for a careful physical examination, an abdominal
ultrasound, a stool analysis, some lab blood tests including: a
complete blood count, PCR, sedimentation rate, CEA, CA19.9 (tumor antigenes), etc.
A GI endoscopy is necessary to exlude possible lesions of the digestive tract if suspicions are raised.
Meanwhile, I agree with your decision to temporary reduce the antihypertesive drugs doses (because of low blood pressure and
dehydration) and take plenty of fluids.
Hope to have been helpful!
Best wishes,
Dr. Iliri