Submitted by That_Guy_Frank t3_z8fxu2 in LifeProTips
Charcoal can be found as a colourant in foods like burger buns, pasta and sausages to give a novelty black colour. This charcoal can effect the absorption of medications such as birth control, some pain medications, antidepressants and probably more into the body.
This effect of this can range from minor (only partially reducing the effective absorbed dose) to complete (the same as not taking the medication at all).
bananadingding t1_iybq397 wrote
Addition to this tip, if you're taking Pepto bismol, it's the chemicals that are solidifying your stool that are causing it to discolor, you are not having internal bleeding.