Hi... Welcome to healthcare magic... According to your complain you have problem of sulfer smell in stool that may be because of gastroenteritis... Infection by bacteria or viral or parasitic cause abdominal bloting problem and diarrhea... Intestinal condition like celiac disease cause foul smell after taking gluten foods... Some food intolerance also cause abdominal symptoms.... Lactose intolerance may ruled out... Stool examination test is helpful to check which infection is present or not... Colonoscopy can done for further diagnosis... Consult a gastroenterologist for further diagnosis.. Detail history and physical examination give exact idea.. I hope my guidance helpful to you... Get well soon. Thank you.