Benzaclin and diarreah(diarrhea)

My 17 yr old son has tried several different oral antibiotics for acne.  Unfortunately, he has not had much success and has some stomach issues.  A few days ago the derm prescribed Benzaclin topical to use.  The first 2 days we observed a significant decrease in redness on acne as well as a slight decrease in acne. He has mostly papules and comodones with occasional pustules.  3 days into the Benzaclin he had diarreah (diarrhea) all day long and felt ill.  On the insert of Benzaclin it talks about severe and even fatal colitis.  Of course, we were extremely concerned.  My son uses the Benzaclin on his chest back and face.  I phoned the pharmasist and on call derm.  They both indicated that they had never heard of severe colitis with the topical preparation and thought it was just a coincidence that he became ill.  
My questions
Have you heard or experienced ill effects of topical Benzaclin?
Could it be possible it was a reaction from using too much since he used it on 2 large areas as well as his face?
He feels fine after one day of being ill, and Benzaclin seems to work so well but am afraid for him to use the product.
Any thoughts or experiences would be greatly appreciated.
As a side note, he has never suffered from the illnesses listed on the insert ie..colitis etc.
Thank YOu,
Cindy

[Alan Rockoff, MD]

I don't think you need to worry.  Oral clindamycin, one of the components of Benzaclin, can cause colitis.  Colitis from topical application of this very commonly used antibiotic is very rare, if it's happened at all.

Best.

Dr. Rockoff

[danny4058]

A related discussion, it happened to me twice was started.

[Ronni713]

A related discussion, Is Colitis cause from Benzaclin(benzol peroxide/clindamycin) reversable? was started.