Intestinal infection (7)
I believe the answer is:
cholera
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">intestinal infection</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for cholera that I've seen before include "could kill you" , "Intestinal infection caused by contaminated water or food" , "Disease caught from contaminated water" , "Acute intestinal infection from contaminated water or food" , "Acute infection caused by contaminated water or food" .)