In order to check the long-term tolerance of a laxative treatment, the authors supervised during six months a group of 14 elderly people (12 women and 2 men) with a mean age of 81.3 years suffering from long-standing constipation without any organic cause. The laxative was given in a daily dosage corresponding to 20 mg of sennosides. Alpha 1-antitrypsin (alpha 1-AT) clearance and exchangeable potassium pool (PPE) were measured, at the beginning (T0), and at the end of the third (T3) and the sixth (T6) months of the study. No abnormal variation of intestinal protein loss (alpha 1-AT: T0, 6.74 +/- 3.16; T3, 2.96 +/- 1.35; T6, 4.15 +/- 1.45 ml/24 h; T0-T3; p less than 0.05, T0-T6, T3-T6: NS) and exchangeable potassium pool (PPE: T0, 19.54 +/- 2.55; T3, 20.29 +/- 3.46, T6, 23.56 +/- 4.92 mEq/kg; T0-T3, T0-T6, T3-T6: NS) was observed. In opposition to current views, all long-term laxative treatments do not necessarily induce significant intestinal protein and potassium losses.