Constipation and colonic transit in Mexican patients.

We read with interest the paper by Carmona et al. in relation to patients consulting for constipation in Mexico. 1 This paper provides further information to a problem in Mexico that has a prevalence ranging from 7 to 19%. 2 However, we must comment on two aspects. First, the Rome III Questionnaire (RIIIQ) was used to diagnose Chronic Constipation (CC) and IBS-C, and although the authors state that they previously translated and validated the questionnaire , 1 there is no mention of the methodology used in that process. Sperber has extensively discussed this critical step and has recognized that the process of translating and adapting a questionnaire into a different language/culture is time and resource consuming, but it is important so that the instrument can be comprehensible, but at the same time maintain the meaning and intent of its original version. Thus, unless the process is carried out successfully, the results of a study using that questionnaire may not be valid. 3 The RIIIQ has been translated into Spanish in a multinational effort in Latin America-including Mexico-and Spain, and is currently under the validation process but not yet available for research studies in our country. 4 Secondly, it is interesting to compare their results with that of a small study that we reported several years ago. 5 We included 18 patients consulting for constipation (83% females); 11 (61%) fulfilled Rome I criteria for IBS-C, 3 (17%) for CC and 4 (22%) had a mixture of IBS-C + CC. These figures are similar to those reported in Carmona's study (IBS-C: 60%, CC: 25%). We measured the colonic transit by administering 24 radiopaque markers during 3 consecutive days (24/3) and abdominal X-rays were given in days 4 and 7. The 72-hour was used as the upper limit for a normal transit, finding that 41% of our patients had normal and 59% prolonged transit times. This is in contrast to the subgroup of 23 patients in Carmona's study that underwent a similar methodology (24/3), from which 59% had prolonged transit times. Although it looks as if we had more patients with a normal transit (59 vs. 39%), these numbers are not different (X 2 : p= 0.218). However, patients in Carmona's study were selected as only those with a prolonged screening transit (24 markers/1 day) underwent the 24/3 evaluation. The fact that 39% (9/23 patients) of those with a prolonged 24/1 had a …