With the current clinical popularity of patient-controlled analgesia pumps (PCAP) in postoperative pain management, it is prudent to be aware of the possible risk of adynamic ileus formation from intravenous narcotic administration. We hypothesized that prolonged PCAP exposure could delay bowel motility and increase post-operative morbidity. After stringent exclusionary parameters were met, we retrospectively analyzed 170 postcesarean patients who received PCAP medication and compared data with 171 postcesarean patients who received traditional intramuscular (IM) administration. The degree of adynamic ileus formation of moderate and severe intensity was higher in PCAP users (21.8%) vs. IM users (13.5%), P = .02. There was no significant difference in the average cumulative amount of analgesic administered during the first 24 postoperative hours for PCAP (442.2 mg) vs. IM (397.7 mg), reflecting that the mode of narcotic delivery is responsible for ileus formation rather than the dosage. Type of postoperative diet and speed of diet advancement were also factored into the analysis and did not statistically influence the results. We conclude that PCAP usage may increase the morbidity risk for adynamic ileus formation, and that usage should be accompanied with close monitoring of bowel motility.