Colitis, which was not defined in the survey documentation, is an inflammatory bowel disease that causes diarrhea. Other variables identify sample adults with inflammatory bowel disease: BOWELINFYR, had inflammatory bowel disease, past 12 months, (2007); BOWELIRINFEV, ever told had inflammatory or irritable bowel (2002, 2007); CROHNEV, had ulcerative colitis and Crohn's disease (1999); and BOWELIRREV (for inflammatory bowel disease and irritable bowel), available for 1989.

For 1989, DIARRTROUBYR identifies adults who "had a lot of trouble" with diarrhea in the past year. The interview question defined "a lot of trouble" as "you saw or talked to a doctor or other health professional, you took medication more than once, or the problem interfered with your life or usual activities."

Information was separately collected, for both sample adults and sample children, on whether the individual had a stomach or intestinal illness with vomiting or diarrhea that had started during the previous two weeks (INTESTILL2WK). According to the Field Representative's Manual for 1998-2000, this question was primarily intended to measure short-lived infectious conditions "such as stomach flu, gastroenteritis, and so forth," not a recurrent or chronic illness like colitis.