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.

Background-Cellular changes associated with diabetic (DG) and idiopathic gastroparesis (IG) have recently been described from patients enrolled in the Gastroparesis Clinical Research Consortium. The association of these cellular changes with gastroparesis symptoms and gastric emptying is unknown.Aim-Relate cellular changes to symptoms and gastric emptying in patients with gastroparesis.Methods-Earlier, using full thickness gastric body biopsies from 20 DG, 20 IG and 20 matched controls, we found decreased interstitial cells of Cajal (ICC) and enteric nerves and an increase in immune cells in both DG and IG. Here, demographic, symptoms (gastroparesis cardinal symptom index score), and gastric emptying were related to cellular alterations using Pearson's correlation coefficients.Results-ICC counts inversely correlated with 4 hours gastric retention in DG but not in IG (r= −0.6, p=0.008, DG, r=0.2, p=0.4, IG). There was also a significant correlation between loss of ICC and enteric nerves in DG but not in IG (r=0.5, p=0.03 for DG, r=0.3, p=0.16, IG). IG with a myenteric immune infiltrate scored higher on the average GCSI (3.6±0.7 vs 2.7±0.9, p=0.05) and nausea score (3.8±0.9 vs 2.6±1.0, p=0.02) as compared to those without an infiltrate. Conclusions-In

Gastroparesis is characterized by symptoms suggesting retention of food in the stomach with objective evidence of delayed gastric emptying in the absence of mechanical obstruction in the gastric outflow. This condition is increasingly encountered in clinical practice. These guidelines summarize perspectives on the risk factors, diagnosis, and management of gastroparesis in adults (including dietary, pharmacological, device, and interventions directed at the pylorus), and they represent the official practice recommendations of the American College of Gastroenterology. The scientific evidence for these guidelines was assessed using the Grading of Recommendations, Assessment, Development, and Evaluation process. When the evidence was not appropriate for Grading of Recommendations, Assessment, Development, and Evaluation, we used expert consensus to develop key concept statements. These guidelines should be considered as preferred but are not the only approaches to these conditions.

Background & Aims Gastroparesis can be diabetic or idiopathic, yet little is known about differences in their presentation. We compared clinical characteristics, symptoms, and gastric emptying in patients with type-1 or -2 diabetic (DG) or idiopathic (IG) gastroparesis. Methods We analyzed data from 416 patients with gastroparesis who were enrolled in the NIDDK Gastroparesis Registry; 254 had IG (most were female and Caucasian), and 137 had DG (78 had type-1 and 59 had type-2). Registry data included detailed histories, physical examinations, results from gastric emptying scintigraphy (GES), and responses to validated symptom questionnaires. Results Patients with type-2 DM were an average of 13 years older at the onset of symptoms of gastroparesis and heavier than patients with IG. Patients with type-1 DM had more hospitalizations in the past year than patients with IG. Symptoms that prompted evaluation more often included vomiting for DG and abdominal pain for IG. Patients with DG had more severe retching and vomiting than those with IG, whereas patients with IG had more severe early satiety and postprandial fullness sub-scores. Compared to IG, gastric retention, was greater in patients with type-1DM. More than 50% of patients with type-1 DM had severe retention (>35% at 4 hours); they took prokinetic agents more frequently and were more likely to receive gastric electric stimulation. Conclusions There are similarities and differences in clinical characteristics of DG and IG. Gastroparesis is a heterogeneous disorder; its etiology affects symptoms and severity. Long-term studies are needed to determine if the differences in symptoms and gastric emptying affect progression and treatment responses.

The ultrastructural changes in diabetic and idiopathic gastroparesis are not well studied and it is not known whether there are different defects in the two disorders. As part of the Gastroparesis Clinical Research Consortium, full thickness gastric body biopsies from 20 diabetic and 20 idiopathic gastroparetics were studied by light microscopy. Abnormalities were found in many (83%) but not all patients. Among the common defects were loss of interstitial cells of Cajal (ICC) and neural abnormalities. No distinguishing features were seen between diabetic and idiopathic gastroparesis. Our aim was to provide a detailed description of the ultrastructural abnormalities, compare findings between diabetic and idiopathic gastroparesis and determine if patients with apparently normal immunohistological features have ultrastructural abnormalities. Tissues from 40 gastroparetic patients and 24 age- and sex-matched controls were examined by transmission electron microscopy (TEM). Interstitial cells of Cajal showing changes suggestive of injury, large and empty nerve endings, presence of lipofuscin and lamellar bodies in the smooth muscle cells were found in all patients. However, the ultrastructural changes in ICC and nerves differed between diabetic and idiopathic gastroparesis and were more severe in idiopathic gastroparesis. A thickened basal lamina around smooth muscle cells and nerves was characteristic of diabetic gastroparesis whereas idiopathic gastroparetics had fibrosis, especially around the nerves. In conclusion, in all the patients TEM showed abnormalities in ICC, nerves and smooth muscle consistent with the delay in gastric emptying. The significant differences found between diabetic and idiopathic gastroparesis offers insight into pathophysiology as well as into potential targeted therapies.

Background Factors associated with abdominal pain in gastroparesis are incompletely evaluated and comparisons of pain versus other symptoms are limited. This study related pain to clinical factors in gastroparesis and contrasted pain/discomfort- with nausea/vomiting-predominant disease. Methods Clinical and scintigraphy data were compared in 393 patients from 7 centers of the NIDDK Gastroparesis Clinical Research Consortium with moderate-severe (Patient Assessment of Upper Gastrointestinal Disorders Symptoms [PAGI-SYM] score ≥3) vs. none-mild (PAGI-SYM <3) upper abdominal pain and predominant pain/discomfort vs. nausea/vomiting. Key Results Upper abdominal pain was moderate-severe in 261 (66%). Pain/discomfort was predominant in 81 (21%); nausea/vomiting was predominant in 172 (44%). Moderate-severe pain was more prevalent with idiopathic gastroparesis and with lack of infectious prodrome (P≤0.05) and correlated with scores for nausea/vomiting, bloating, lower abdominal pain/discomfort, bowel disturbances, and opiate and antiemetic use (P<0.05) but not gastric emptying or diabetic neuropathy or control. Gastroparesis severity, quality of life, and depression and anxiety were worse with moderate-severe pain (P≤0.008). Factors associated with moderate-severe pain were similar in diabetic and idiopathic gastroparesis. Compared to predominant nausea/vomiting, predominant pain/discomfort was associated with impaired quality of life, greater opiate, and less antiemetic use (P<0.01), but similar severity and gastric retention. Conclusions & Inferences Moderate-severe abdominal pain is prevalent in gastroparesis, impairs quality of life, and is associated with idiopathic etiology, lack of infectious prodrome, and opiate use. Pain is predominant in one fifth of gastroparetics. Predominant pain has at least as great an impact on disease severity and quality of life as predominant nausea/vomiting.