Upper Gastrointestinal and Esophageal
Upper GI disorders in patients with SLE are common and occur in greater than 50% of patients.  Gastointestinal Reflux or heartburn is most frequent and can be difficult to treat.  The underlying etiology is not completely clear however gastrointestinal motility appears to play a major cause with impairments in gastric emptying and decreased esophageal peristalsis.
Heartburn can be very troublesome and may require combination treatment with twice daily proton pump inhibitor, in addition to sucralfate taken between meals.  Nausea and vomiting are manifestations of gastroparesis or severe incomplete emptying of the stomach and occur in 5-10% of SLE patients.  Vomiting of undigested food occurs with this disorder.  Some of the early symptoms include loss of appetite while eating and early satiety.  Treatment includes diet modifications with frequent small meals, lower residue diet, and medications including metoclopramide, tegaserod, or domperidone.
Dysphagia, which manifests itself as difficulty swallowing typically solids but often both solids and liquids occurs in more than 25% of patients with Lupus.  Symptoms may be intermittent and may lead to progressive weight loss and even obstructive symptoms while eating solids such as breads or meat especially if not well chewed.  Endoscopic treatment is effective in most patients.  During the endoscopy esophageal dilation using Maloney dilators or balloon dilators is effective in most patients for restoring normal swallowing sensation and ability.  This disorder may require periodic dilations in combination with daily acid blockers.
Small Intestine and Colon
Motility disorders account for most of the small intestinal disorders in Lupus patients.  Poor motility leads to overgrowth of bacteria in the small bowel which occurs in 10-20% of patients with Lupus.  Bacterial overgrowth can in turn lead to malaborption of fats and steatorrhea with weight loss, diarrhea and fat soluble vitamin loss or iron deficiency anemia.  Diagnostic testing including the lactulose breath test, D-Xylose test can confirm the diagnosis and treatment consists of broad spectrum antibiotics such as Ciprofloxacin, metronidazole or more recently Rifaximin may have efficacy.  Perhaps the most devastating gastrointestinal complication of SLE  is mesenteric vasculitis characterized by inflammation of the ileum (lower small bowel) and colon.  This can result in severe bleeding, hemorrhage or even bowel perforation.  Treatment with steroids, cyclophasphamide or anti-coagulation in certain setting may be beneficial.
Chronic pancreatitis has been described in Lupus but is thought to be rare and occurs in less than 5% of patients.  Symptoms include recurrent bouts of nausea, vomiting, abdominal pain which may radiate to the back.  The cause is unclear and elevations of amylase and lipase may or may not be present to confirm the diagnosis.  Treatment largely consists of a low fat diet and supplementation with pancreatic digestive enzymes such as Creon or Viokase.