Background: Vomiting is usually a late and an infrequent symptom of colonic obstructions. Contrary to this general rule, it occurs early and more frequently in some cases of sigmoid volvulus. Aim: To study the clinical significance of vomiting in patients with sigmoid volvulus. Setting: Teaching hospital in Western Orissa, India Study Design: Prospective observational study Material and Methods: Prospectively enrolled subjects with sigmoid volvulus diagnosed on the basis of clinical, radiological and laparotomy evidence were included in the study carried out in a tertiary care centre in India. Detailed history was obtained from them, especially to elicit information about the occurrence of various symptoms. Information regarding type of vomiting was also obtained. Efforts were made to exclude other causes of vomiting. Statistical tests such as Chi-Square test, Fisher's exact test or Student's t test were used. Results: Ninety-three consecutive subjects with sigmoid volvulus were enrolled. Five patients with possible other aetiologies for vomiting and seven patients with compound sigmoid volvulus were eliminated from further analysis. Two patterns of vomiting were noted in 81 evaluable patients with sigmoid volvulus. In 33 patients (Group A), vomiting preceded or coincided with the onset of other abdominal symptoms (Type 1 vomiting). In 48 patients (Group B) vomiting occurred after the onset of other abdominal symptoms (Type 2 vomiting). The period between the onset of these symptoms and that of vomiting varied from a few hours to several days. Group A patients sought medical help much earlier than those of Group B. Incidences of circulatory shock (24% vs. 8%), haemorrhagic ascites (21% vs. 6%) and colonic gangrene (64% vs. 35%) were significantly higher in Group A than in Group B. The mortality rate (15% vs. 4%) was higher in Group A as well. About 25% (n = 7) of Group A patients in contrast to 4% (n=2) of Group B required hospitalization exceeding 3 weeks. Vomitus was predominantly non-bilious (21 out of 33 patients) in Group A (64%) and bilious (10 out of 11 patients) in Group B (91%). Conclusion: Type 1 vomiting appears to be an indicator of more severe presentation and is associated with an increased morbidity and mortality. This study suggests that the pattern of vomiting could be a simple and useful predictor of prognosis in sigmoid volvulus
