( Mahonia aquifolium )
This herb and its herberine containing cousins, goldenseal, gold thread, and barberry, fights a broad range of microbes. The studies have found, that berberine is effective in diarrhea caused by bacteria such as shigella, salmonella, E. coli, and V, cholerae, and by the parasite giardia. The typical dosage of tincture is 60 drops 3x a day, If taken capsules than you would need 500 to 600 milligram taken up to 6x a day.
There is a caution , Do not use herbs containing berberine during pregnancy.
Note Children do not get as much as a adult, it is 1/2 the dosage of and adult.