Effects - extremely unpleasant experience eating pod grounds

[jslice]

SWIM has been drinking tea and/or eating grounds for the past 3 months (same source) or so and this is the only time this has happened so far.

SWIM ingested aroung 20 grams of grounds (on an empty stomach) dampened in water and had no trouble getting them down.
Around a half hour to an hour later SWIM experienced some of the most grueling stomach pain he had ever felt on opiates(or anything else he could remember), SWIM proceeded to lie down and pass out around 30 minutes later. SWIM woke up an hour and a half later and threw up for the next 2 hours.

SWIM hasnt been able to bring himself to eat the grounds since then and has been making tea again instead.

SWIM is curious as to what have might caused this reaction.