Background-Cellular changes associated with diabetic and idiopathic gastroparesis are not well described.Aim-Describe histologic abnormalities in gastroparesis and compare findings in idiopathic versus diabetic gastroparesis.Methods-Full thickness gastric body biopsies were obtained from 40 gastroparetics (20 diabetic) and matched controls. Sections were stained for H&E and trichrome, and immunolabeled with antibodies against PGP 9.5, nNOS, VIP, substance P and tyrosine hydroxylase to quantify nerves, S100β for glia, Kit for interstitial cells of Cajal (ICC), CD45 and CD68, for immune cells and smoothelin for smooth muscle cells. Tissue was also examined by transmission electron microscopy (TEM).Results-Histological abnormalities were found in 83% of patients. Most common defects were loss of ICC with remaining ICC showing injury, an abnormal immune infiltrate containing macrophages, and decreased nerve fibers. On light microscopy, no significant differences were found between diabetic and idiopathic gastroparesis with the exception of nNOS expression which was decreased in more idiopathic gastroparetics (40%) compared to diabetic (20%) patients by visual grading. On electron microscopy, a markedly increased connective tissue stroma was present in both disorders.Conclusion-This study suggests that on full thickness biopsies, cellular abnormalities are found in the majority of patients with gastroparesis. Most common findings were loss of Kit expression suggesting loss of ICC and an increase in CD45 and CD68 immunoreactivity. These findings suggest that examination of tissue can lead to valuable insights into the pathophysiology of these disorders and offers hope that new therapeutic targets can be found.

Background & Aims Idiopathic gastroparesis (IG) is a common but poorly understood condition with significant morbidity. We studied characteristics of patients with IG enrolled in the NIDDK Gastroparesis Clinical Research Consortium Registry. Methods Data from medical histories, symptom questionnaires, and 4-hour gastric emptying scintigraphy studies were obtained from patients with IG. Results The mean age of 243 IG patients studied was 41 years; 88% were female, 46% were overweight, 50% had acute onset of symptoms, and 19% reported an initial infectious prodrome. Severe delay in gastric emptying (>35% retention at 4 hours) was present in 28% of patients. Predominant presenting symptoms were nausea (34%), vomiting (19%), and abdominal pain (23%). Women had more severe nausea, satiety, constipation and overall gastroparesis symptoms. Patients who experienced acute onset IG had worse nausea than those with insidious onset. Overweight patients had more bloating and gastric retention at 2 hours, but less severe loss of appetite. Patients with severely delayed gastric emptying had worse vomiting, more severe loss of appetite and overall gastroparesis symptoms. Severe anxiety and depression was present in 36% and 18%, respectively. 86% met criteria for functional dyspepsia, primarily postprandial distress syndrome. Conclusions IG is a disorder that primarily affects young women, beginning acutely in 50% of cases; unexpectedly, many patients are overweight. Severe delay in gastric emptying was associated with more severe symptoms of vomiting and loss of appetite. IG is a diverse syndrome that varies by sex, body mass, symptom onset, and delay in gastric emptying.

Background & Aims Chronic nausea and vomiting with normal gastric emptying is a poorly understood syndrome; we analyzed its characteristics. Methods We collected and analyzed data from 425 patients with chronic nausea and vomiting, enrolled at 6 centers by the Gastroparesis Clinical Research Consortium in the National Institute of Diabetes and Digestive and Kidney Diseases Gastroparesis Registry. Results Among the patients, 319 (75%) had delayed emptying, defined by the results of a standardized, low-fat meal, and 106 had normal gastric emptying. Patients with or without delayed emptying did not differ in age, sex, or race, although those with normal gastric emptying were less likely to be diabetic. Symptom severity indices were similar between groups for nausea, retching, vomiting, stomach fullness, inability to complete a meal, feeling excessively full after meals, loss of appetite, bloating, and visibly larger stomach. There were no differences in health care utilization, quality of life indices, depression, or trait anxiety scores. However, state anxiety scores were slightly higher among patients with delayed gastric emptying. Total gastroparesis cardinal symptom index scores were not correlated with gastric retention after 2 or 4 hours in either group. Patients with the syndrome were not adequately captured by the stand-alone criteria for the Rome III diagnoses of chronic idiopathic nausea and functional vomiting. With rare exceptions, the diagnosis remained stable after a 48-weeks follow-up period. Conclusions Patients with nausea and vomiting with normal gastric emptying represent a significant medical problem and are, for the most part, indistinguishable from those with gastroparesis. This syndrome is not categorized in the medical literature—it might be a separate clinical entity.