Summary:Patients often develop nausea, vomiting and bloating after bone marrow transplantation (BMT). These symptoms may interfere with nutrition and the ability to take oral medications. Gastroparesis is a recognized cause of these symptoms in non-transplant patients but less is known about patients who undergo BMT. Between January 1996 and March 1997, a total of 151 patients underwent BMT. Eighteen patients (12%) developed persistent symptoms suggestive of gastroparesis (persistent nausea, vomiting or bloating). Scintigraphic gastric emptying studies were performed to assess for gastroparesis. Prokinetic agents were administered at the time of study. The records on these patients were compared with those of all other patients undergoing BMT during the same time period without these symptoms. Nine patients who demonstrated delayed gastric emptying were further evaluated with esophagastroduodenoscopy and biopsy. Biopsy samples were reviewed for evidence of graft-versus-host disease (GVHD). Fourteen of 18 patients demonstrated delayed gastric emptying and most responded to prokinetic agents given at the time of study. Age, conditioning regimen, cytomegalovirus antigenemia and acute GVHD did not appear to be associated with the development of gastroparesis. Allogeneic BMT recipients were at higher risk than autologous BMT patients (26% vs 0%, P Ͻ 0.0001). Of allogeneic BMT recipients, there was a nonsignificant trend of patients receiving tacrolimus to be less likely to experience gastroparesis than those receiving cyclosporine (27% vs 48%, P = 0.08). For the nine patients undergoing upper endoscopy, GVHD on gastric biopsy was an uncommon finding and was mild when present. Gastroparesis appears to be a common cause of nausea, vomiting and bloating following allogeneic BMT. This may occur less often with tacrolimus than cyclosporine because of the former agent's prokinetic properties. Keywords: gastroparesis; hematopoietic cell transplant; gastric emptying; nausea and vomiting Following bone marrow transplantation (BMT), some patients develop persistent nausea, vomiting, bloating, early satiety and decreased tolerance to oral nutrition and medications. These symptoms frequently develop weeks after transplantation and inhibit weight gain, optimal nutrition and the transition from intravenous to oral medications.Gastroparesis is a disorder of motor function of the stomach in which gastric emptying is delayed. Patients with gastroparesis often develop symptoms of nausea, vomiting, bloating and distension. Gastroparesis has many known causes which include atrophic gastritis, diabetes, hypothyroidism, uremia, scleroderma, anticholinergics and stress. 1 Additionally, cytomegalovirus (CMV), herpes simplex virus (HSV) and other viral infections have been implicated as causes of delayed gastric emptying. 1,2 We performed gastric emptying studies on patients presenting with persistent nausea, vomiting and bloating following allogeneic or matched unrelated donor transplantation to assess for underlying gastroparesis and to as...