Boiled olive leaves
I boil a handful olive leaves every day and make it into 3 glasses and only consume only one per day. I feel that the dosage is not right after experiencing stomach ache and diarrhoea. It makes me wonder how many leaves should I boil and how should I boil them. Any suggestion on this case?
It sounds like your extract is either too strong or your leaves may be contaminated with something - for example some type of spray.
A third possibility is that you have a Candida-like yeast/fungal or bacterial overgrowth in your gut and the olive leaf is attacking it too aggressively.
I think the first and third possibilities are probably the most likely, as a handful of olive leaves - assuming they are a suitable variety - will pack a powerful antimicrobial punch.
I suggest taking a small quantity of leaves chopped up, such as what you would find in a normal teabag, pour boiling water over it and steep for 10 minutes.
Try drinking that and see if you have a reaction.
If not, you can try boiling that small quantity for a few minutes and drink it. The longer you boil, the more bitter it will taste, so if you are drinking it as a pleasant healthy beverage, just prepare it as you would any other tea.
If it is to treat a condition of some sort, increase the strength slowly so that it doesn't give you the symptoms you described.
If you still get a stomach ache, try purchasing some capsules or a tincture and see if you have the same reaction. No adverse reaction would indicate a problem with your leaves.