Ugh.. it took me some time to notice a pattern and come to the conclusion that..

the multivitamins that I recently bought also act as a mild laxative.

I often forget to take them so it's like every couple days. But as I sit preoccupied on the can, I was wondering what could have caused my gastronomic distress that I've also felt fairly often recently, and there seems to be only one common factor.

or perhaps, your body is so relieved after absorbing the nutrients that it's like "fuck yes resume normal operations boys we got enough fluid to plop some turds out again"

magnesium makes you shits

It probably contains magnesium oxide. This common multi-vitamin additive is also used as an antacid and a laxative.

Make sure that you're taking your vitamins with a full meal. This should help reduce the effects. Taking vitamins with food also improves absorption, especially of the fat soluble vitamins A, D, E, and K. More fiber in your diet should help as well. Magnesium draws water from the surrounding tissues by osmosis; fiber will absorb some of this excess water.

Excipients are a bitch.

Good to know; thanks. I actually used to be really good on my fiber intake, but I've dropped the ball.