I took ampicillin 250mg around 12am but I am constipated and I want to take a laxative is it OK to take it 12hours later?

Yes. Some antibotics do cause that. I use Senna, a natural laxative, with the Store brand, like Dollar General, or Family Dollar, etc. It doesn't cost as much as the brand name, but it's the same thing. Any laxative will be O'K. It's your choice. Good luck.

Sam, please don't give medical advice if you aren't a medical professional.

This child should not take ANYTHING without consulting the Physician who prescribed the antibiotics OR she should ask her Pharmacist.

Your advice could be dangerous.

Diarrhea is a known side effect of this medication, not constipation.

This person needs to discuss the problem with a Physician. She had taken 1 dose 12 hours ago and has no idea if diarrhea will result. Taking a laxative on top of possible diarrhea is not safe.

I realize this is not what your Doctor told you, but I am not certain you were on the same medication under the same circumstances - 1 dose, constipated 12 hours later.