In advanced cancer patients with inoperable bowel obstruction, the administration of antisecretive and antiemetic drugs has proved to be effective in controlling gastrointestinal symptoms caused by bowel obstruction. However, controlled studies concerning the most effective antisecretive drug are lacking. The aim of this randomized controlled study was to determine whether octreotide or hyoscine butylbromide was the more effective antisecretive drug for use in states of inoperable bowel obstruction. Eighteen patients with inoperable bowel obstruction randomly received octreotide 0.3 mg daily (n = 9) or hyoscine butylbromide (HB) 60 mg daily (n = 9) s.c. The following parameters were measured: episodes of vomiting, nausea, drowsiness, continuous and colicky pain, using a Likert scale corresponding to a numerical value: (none 0, slight 1, moderate 2, severe 3) recorded before starting the treatment (T0) and 24 h (T1), 48 h (T2) and 72 h after (T3), and the mean daily amounts of fluids administered i.v. or s.c. during the period of study. Three patients dropped out of the study because data were incomplete. Octreotide treatment induced a significantly rapid reduction in the number of daily episodes of vomiting and intensity of nausea compared with HB treatment at the different time intervals examined. No relevant changes were found in dry mouth, drowsiness and colicky pain. Lower levels of hydration were associated with nausea regardless of the treatment. At the doses used in this study, octreotide was more effective than HB in controlling gastrointestinal symptoms of bowel obstruction. Further studies are necessary to understand the role of hydration more clearly in such a clinical situation.