Took 12 benadryl over the course of one day, and 8 or 9 each day for the few before that. was within the max dose on the bottle, but had bad stomach pain the past 3 days. i stopped taking the ben when it started hurting. is this bad, or just my ibs?

Or just the Benadryl. Go to Drugs.com and read about Ben and then if you are taking any other meds do interaction check with them. Then discuss with your Dr.

Benadryl is not a suitable medication to treat IBS. Do you mean you were taking BENTYL which is an effective antispasmodic for treatment of IBS? 20 mgs every 6 hours would be the maximal dose but can also cause severe constipation, bloating & nausea at that dose. Check the label on the medicine bottle.