Black stools, most of the times, denote
Gastrointestinal bleeding and could be due to
lactose intolerance, divertculosis, Aspirin use, IBS, Iron supplement intake.
Scanty periods may be due to premenopausal stage (I don't know your age), hormonal imbalance, emotional stress, intense physical activity, PCOS etc. Could be anaemia too.
One has to correlate clinically.
Ideally we always suggest to our patients Tab Styplon by Himalya co. known for quality Ayurvedic Medicine. This tab is safe, no side effects. It will check
internal bleeding due to any reason. Kaharwa pishti and Prawal Pishti and Nagkeshar hebal powder ( Mesua ferrea) with honey will control GI bleeding due to any cause and relieve cramps.
Liquid Ashokarishta and sy Evecare are excellent uterine tonics for scanty menses, other hormonal imbalance at
menarche or
menopause. These are pure herbal friends if women. Unparalleled in allopathy.
You may find these anday also seek help of any Ayurveda doctor.
Hope it helps you.