▁which ▁inf ect s ▁the ▁large ▁int est ine . ▁Phys icians ▁report ▁that ▁patients ▁with ▁in fection ▁show ▁sympt oms ▁of ▁ab dom inal ▁pain , ▁const ip ation , ▁and ▁di arr he a . ▁One ▁study ▁found ▁that ▁ 4 3 % ▁of ▁I BS ▁patients ▁were ▁inf ected ▁with ▁Bl asto c yst is ▁versus ▁ 7 % ▁of ▁controls . ▁ ▁An ▁additional ▁study ▁found ▁that ▁many ▁I BS ▁patients ▁from ▁whom ▁Bl asto c yst is ▁could ▁not ▁be ▁identified ▁showed ▁a ▁strong ▁ant ib ody ▁reaction ▁to ▁the ▁organ ism , ▁which ▁is ▁a ▁type ▁of ▁test ▁used ▁to ▁diagn ose ▁certain ▁difficult - to - det ect ▁in fe ctions . ▁Other ▁research ers ▁have ▁also ▁reported ▁that ▁special ▁testing ▁techniques ▁may ▁be ▁necessary ▁to ▁identify ▁the ▁in fection ▁in ▁some ▁people . ▁ ▁While ▁some ▁scient ists ▁believe ▁the ▁finding ▁that ▁I BS ▁patients ▁carry ▁a ▁proto zo al ▁in fection ▁to ▁be ▁significant , ▁other ▁research ers ▁have ▁reported ▁their ▁belief ▁that ▁the ▁presence ▁of ▁the ▁in fection ▁is ▁not ▁med ically ▁significant . ▁ ▁Research ers ▁report ▁that ▁the ▁in fection ▁can ▁be ▁resist ant ▁to ▁common ▁proto zo al ▁treat ments ▁in ▁labor atory ▁culture ▁study , ▁and ▁in ▁experience ▁with ▁patients , ; ▁therefore , ▁ident ifying ▁Bl asto c yst is ▁in fection ▁may ▁not ▁be ▁of ▁immediate ▁help ▁to ▁a ▁patient . ▁A ▁ 2 0 0 6 ▁study ▁of ▁g astro int est inal ▁in fe ctions