Background: Recent investigations suggested the association between use of proton pomp inhibitor (PPI), and Clostridium difficile infection and fracture/osteoporosis, which inflammatory bowel disease (IBD) patients are at risk for both. Methods: We investigated the frequency of PPI use and upper gastrointestinal (GI) symptoms, i.e., gastroesophageal reflux disease (GERD) and functional dyspepsia (FD) in IBD outpatients. Participants were invited and agreed to participate in this study at their regular follow-up visit in our institution between June and September 2011. Patients with symptomatic upper GI Crohn’s disease were excluded. A self-administered questionnaire was given to evaluate age, sex, body mass index, smoking history, IBD diagnosis, age at IBD onset, surgical history, current and past IBD medications, use of antipsychotics, NSAIDs, histamine 2 antagonist and PPI. Concomitant GERD and FD were diagnosed by the questionnaire according to Montreal definition and Rome 3 criteria, respectively. Results: Total 272 (164 male and 108 female) patients were evaluated. 193 UC and 78 CD patients were included. Average age was 41.1±15.1 (S.D.) yrs. Disease duration was 6.0 yrs (median). 33 patients (12.2%) had a history of laparotomy. 21 (7.8%) and 67 (24.9%) patients were current and past smokers, respectively. Medications being used were 5-ASA in 184 (67.6%) , corticosteroid (CS) in 9 (3.3%) , immunomodulator in 109 (40.1%) , tacrolimus in 12 (4.4%) , and biologics in 57 (21.0%) patients. GERD and FD were complicated in 28 (10.3%) and 75 (27.6%) patients each. PPI users (n = 26) and non-users (n = 246) were compared. Compared with non-users, users were older (49.1 vs 40.2 yrs, p = 0.004), used more often CS (past or current) (84.6% vs 43.1%, p < 0.0001), antipsychotics (38.5% vs 12.6%, p = 0.0018) and NSAIDs (23.1% vs 9.4%, p = 0.043). Users were complicated more frequently by GERD (26.9% vs 8.6%, p = 0.0098) and FD (57.7% vs 24.4%, p = 0.0008). In a multiple regression analysis, age (odds ratio, 1.040 (95%C.I., 1.012 1.068), p = 0.005), current or past CS use (odds ratio, 6.647 (95%C.I., 2.170 20.357), p = 0.001), and having GERD or FD (odds ratio, 3.152 (95%C.I., 1.308 7.599), p = 0.011) were all independently associated with PPI use. Conclusions: PPI users were older and were associated with use of other medications such as CS, antipsychotics, and NSAIDs, as well as upper GI symptoms.