Have you been told by your doctor that Zegerid is the cause for diarrhea?
I think that diarrhea is not due to Zegerid usage.
I guess you have been taking it along with antibiotics to treat duodenal or gastric ulcer caused by bacterial infection ( Helicobacter Pylori)

What kind of antibiotics you were taking?
When have you stopped taking the medications?

after taking Zegerid for only a week, all of a sudden i have had diarrhea for 5 days. i have stopped the meds and my doctors are stumped. i actually had to go into the hospital on day 2 to get fluids in me due to dehydration. I am not throwing up anymore but am on day 5 of diarrhea. can't think of anything else that could be the cause.

Acctually, I found some informations about side effects of Zegerid.
It says that diarrhea is second most prominent side effect after headache(these side effects occur in 1 % of people using Zegerid, so, it means are very rare)
Vomiting and nausea are also side effects that appear less frequently.

Were you prescribed Zegerid for treating acid reflux?