To examine the applicability across subgroups of the Manning criteria commonly used to diagnose the irritable bowel syndrome, a 22-item symptom questionnaire was administered to male and female African-American and Caucasian adults (N=1344). Principal components factor analysis with varimax rotation was used to identify symptom clusters. Consistent with the findings of a previous factor analytic study, three of the six Manning symptoms (loose stools and more frequent bowel movements with onset of pain, pain relieved by defecation) formed a cluster corresponding to the irritable bowel syndrome in all subgroups. It is concluded that: (1) The three core Manning symptoms have equal applicability to both genders and to African-Americans as well as to Caucasians. They are useful symptom criteria for the diagnosis of IBS when used in conjunction with medical evaluation. (2) Three of the six Manning symptoms rarely correlate with the others; if confirmed in patient samples, this would indicate that these three symptoms are not useful for making a diagnosis of the irritable bowel syndrome. © 1995 Plenum Publishing Corporation.