Ballard Medical Products said Thursday it agreed to acquire closely held Tri-Med Specialties Inc., a company that makes diagnostic tests for the bacterium that causes stomach ulcers, for $26 million in stock.

Draper-based Ballard Medical Utah, makes medical products for neurological and vascular surgery. It had sales of $34.1 million for the quarter ended Dec. 31.Tri-Med, based in Lenexa, Kansas, makes products that help diagnose the peptic ulcer bacterium, helicobacter pylori.