AbstractINTRODUCTION Gastric outlet obstruction (GOO) is obstruction in the first part of duodenum secondary to cicatrised duodenal ulcer or proximally where the diagnosis of carcinoma is most probable. GOO can be a diagnostic and treatment dilemma. Once a mechanical obstruction is confirmed, differentiate between benign and malignant processes. Cicatrized duodenal ulcer was the most common cause of GOO. But with increased awareness, change in the dietary habits and availability of H2 receptor blockers and Proton Pump Inhibitors and H pylori kits all have resulted in decreased incidence of patients requiring surgery and also the complications like pyloric stenosis have reduced. At the same time the incidence of antral carcinoma of stomach producing GOO has comparatively increased, which may be due to increased early diagnosis of the condition with the help of flexible fibro optic endoscope. AIMS & OBJECTIVES To study and identify the cause of cases of GOO with respect to benign peptic ulcer and malignancy of stomach. MATERIALS AND METHODS An observational study comparing of 30 cases of GOO. An elaborate study of the cases with regard to history, clinical features, routine and special investigation, pre operative treatment, operative findings, post operative management and complications in the post operative period is done. Apart from routine surgical profile special investigations like serum electrolytes, barium meal study, Upper GI Endoscopy and ultrasound abdomen and pelvis will be carried. For peptic ulcer disease truncal vagotomy with posterior gastrojejunostomy was done and for carcinoma partial gastrectomy with Billroth II reconstruction or anterior GJ or palliative resection with anterior GJ were done. INCLUSION CRITERIA 1. Peptic ulcer disease 2. Carcinoma pyloric antrum, 3. Benign neoplasm of stomach. EXCLUSION CRITERIA 1. Carcinoma stomach with liver metastasis, ascites, peritoneal implantation, 2. Gastro duodenal tuberculosis. ETHICAL ISSUES Informed written consent will be taken from patients before including them in the study. SUMMARY OF RESULTS 1. The most common cause of gastric outlet obstruction is carcinoma stomach with antral growth in 53.3% producing GOO in the study. 2. Number of cases with cicatrized duodenal ulcer causing GOO were 43.3%. 3. One case of stenosis following corrosive acid ingestion was also present as the reason for GOO in the study 3.3%. 4. Males are more commonly affected than female and the male female ratio is 7:1 in malignancy. 5. This study was undertaken in an adult rural population. 6. The most common presenting complaints were vomiting (100%), abdominal pain (90%) and loss of appetite (90%). In malignant cases loss of weight (93%) was also a common complaint. 7. Visible gastric peristalsis and succession splash were less prominent in malignant cases when compared to stenosing duodenal ulcer cases. 8. 31% of the malignant cases presented with mass in the upper abdomen. 9. Only 5 cases of malignancy could be able to undergo definite surgical procedure. All others underwent palliative procedures.10.The surgical procedure undertook in the cicatrized duodenal ulcer patients were truncal vagotomy and posterior GJ and there were no recurrence of symptoms in any of the casers which turned up for follow up. 11. The mortality rate was 18.8% in malignant cases. CONCLUSION 1. The most common cause of gastric outlet obstruction in adults are carcinoma stomach with antral growth producing GOO in 53.3% and cicatrized duodenal ulcer causing GOO were 43.3%. 2. In the vast majority of cases the diagnosis can be established clinically. 3. The saline load test was found to be effective bedside investigations to assess the degree of GOO. 4. Upper GI endoscopy should be mandatory in all suspected cases of GOO. 5. Number of cases with cicatrized duodenal ulcer as the chief etiological factors for GOO is diminishing and the number of cases of antral carcinoma of stomach as the cause of GOO is increasing. 6.Effective treatment in carcinoma stomach depends on early diagnosis.