BACKGROUND: The spectrophotometric probe, which uses bilirubin as a marker for the detection of duodenoesophagic reflux is subject to interference from strongly colored foods, which can cause erroneously high bilirubin absorbance readings. To overcome this problem it is necessary to ingest a diet that is free from such substances. OBJECTIVE: To test the absorbance of 48 different food substances in an in vitro environment. MATERIAL AND METHOD: Dry foods were blended with water or milk and non-dry solid foods were blended undiluted. It was utilized the proper calibration recipient to test them. RESULTS: The absorbance of weakly colored foods was usually lesser than the commonly accepted threshold of 0.14, and the absorbance of strongly colored foods was usually above this. Thirty-two from the 48 substances tested are suitable when the absorbance threshold is set at 0.14, but scrambled eggs, lacteous flour mush, green beans, beetroot, carrot, chayote, squash, "baroa" potato, boiled corn, orange, cashew, purple grape, avocado, mango, papaya and peach can alter the results and must be avoided. CONCLUSION: From the foods evaluated, enough are suitable at the 0.14 threshold to enable a suitable diet to be constructed for most patients during Bilitec studies.
Duodenogastric reflux; Gastroesophageal reflux; Bile reflux; Esophagitis, peptic; Spectrophotometry; Diet
