The use of symptomatic agents has greatly improved the medical treatment of advanced cancer patients with inoperable bowel obstruction. A systematic review of studies of the most popular drugs used in the medical management of inoperable malignant bowel obstruction was performed to assess the effectiveness of these treatments and provide some lines of evidence. Randomized trials that involved patients with a clinical diagnosis of intestinal obstruction due to advanced cancer treated with these drugs were reviewed. Five reports fulfilled inclusion criteria. Three studies compared octreotide (OC) and hyoscine butylbromide (HB), and two studies compared corticosteroids (CSs) and placebo. Globally, 52 patients received OC, 51 patients received HB, 37 patients received CSs, 15 patients received placebo, and 37 patients received both placebo and CSs. On the basis of these few data, the superiority of OC over HB in relieving gastrointestinal symptoms was evidenced in a total of 103 patients. The latter studies had samples more defined in terms of stage and inoperability, and had a shorter survival in comparison with studies of CSs (less than 61 days, most of them less than 20 days). Data on CSs are less convincing, due to the methodological weakness of existing studies. This review confirms the difficulties in conducting randomized controlled trials in this population.