Hello. I am your physician here. I would like to answer ur Question in a simplified way to satisfy u. U told u had SMA surgery. SMA syndrome(disease) itself causes compression(blockage)of small intestine(duodenum). It causes Nausea(ur problem), vomiting, early satiety, abdominal pain after the meals, pain to touch the abdomen, heartburn, abdominal distension. If I was ur surgeon I prefer to do Duodenojejunostomy(Making a connection between Duodenum and Jejunum). Note:- If it fails it may cause symtoms after surgery too( as u r observing right now) Also u had Cholecystectomy. It causes some problems with heavy and fatty meals and u have to take small but frequent meals. Less fat in diet. It seems that ur intestines have less motility. Because of that there is chronic constipation and fecal impaction. IT CAUSES NAUSEA VOMITING AND SEVERE PAIN IN STOMACH AREA. I also advise u to consult ur physician in person for any kind of Cancer of Gastrointestinal Tract(God Forbid). Take high fiber diet, while grains, whole wheat bread. Take plenty of fluids, make habit of brisk walk and jogging 4,5times a week. It will make u fee better in every way. If u have further Questions fell free to consult me anytime. I hope u get better soon. Keep relax as much as u can. Feel calm and contented and come out of post surgery trauma. Stay blessed