Dumping syndrome is diagnosed based on a group of symptoms in patients who have undergone gastric surgery, or by the dumping provocation test. In 1970, Sigstad [12] proposed a scoring system based on the occurrence of different symptoms of dumping syndrome, to calculate a diagnostic index (Table 13.1). A diagnostic index > 7 is suggestive of dumping syndrome. This system is simple to use, but its disadvantage is that it is difficult to distinguish other postprandial symptoms from dumping. The score index is helpful in clinical practice to assess response to therapy.

A provocative test for assessing dumping syndrome can be used to confirm clinical suspicions. This test is a modification of the oral glucose tolerance test (OGTT) and involves the ingestion of 50 or 75 g glucose in solution after an overnight fast. Immediately before and up to 180 min after ingestion of this solution, the blood glucose concentration, hematocrit, pulse rate, and blood pressure are measured at 30 min intervals. The provocative test is considered positive if late (120–180 min) hypoglycemia occurs, or if an early (30 min) increase in hematocrit of more than 3 % occurs. The best predictor of dumping syndrome seems to be a rise in pulse rate of more than 10 bpm (beat per min) after 30 min [13]. Assessments of the speed of gastric emptying might show that this process occurs rapidly in patients with dumping syndrome—especially for liquid nutrients—but this test does not seem to have good diagnostic sensitivity or specificity, probably because rapid emptying occurs early after meal ingestion, a phase that is not analyzed closely or separately in most protocols that test gastric emptying [10, 13, 14].

Prevention, rather than treatment, is recommended for dumping syndrome. The introduction of proton pump inhibitors and Helicobacter pylori eradication decrease the need for elective surgery in peptic ulcer disease. In addition, highly selective gastric vagotomy, which causes minimal disturbance of the gastric emptying mechanism, results in a lower incidence of dumping syndrome [15]. If more extensive surgery is necessary, a Roux-en-Y gastrojejunostomy (RYGJ) is preferable because of its decreased rate of dumping, when compared with pyloroplasty or loop gastrojejunostomy [16–18].

The choice of reconstructional method after distal gastrectomy is still controversial. The use of the Billroth I procedure after distal gastrectomy is preferred in Japan, whereas Billroth II is more common in Korea because it facilitates wider dissection and less anastomotic tension. There are some advantages in Billroth I compared to Billroth II, as follows: a more natural route for food passage, potentially less operative time due to one anastomosis, no risk of duodenal stump leakage, and less incidence of postoperative weight loss, anemia, and dumping syndrome. The disadvantage of Billroth I, however, is that the dissection area can be limited in order to facilitate a tension-free anastomosis. Therefore, the Billroth I procedure is commonly used for benign disease or distally located EGC in Korea. However, Kim et al. [19] compared results from 122 gastric carcinoma patients undergoing Billroth I and Billroth II gastrectomy. They evaluated postgastrectomy syndrome with a survey of abdominal symptoms, and dumping syndrome was measured using the Sigstad dumping score. According to their results, the occurrence of abdominal symptoms and dumping syndrome was lower in the Billroth I group than in the Billroth II group. Furthermore, pylorus-preserving gastrectomy (PPG) is a kind of reduced-gastric operation that preserves the distal portion (1.5 cm) of the gastric antrum and reduces postoperative complications such as dumping syndrome and reflux esophagitis [20]. However, a limitation of this operation is that complete lymph node (LN) dissection of the suprapyloric LN is undesirable for the preservation of the pyloric branch of the vagus nerve. Nowadays, some reports state that this procedure may be applicable in EGC confined to the mucosa and located at the gastric mid-body [21].

According to a recent Japanese large-scale investigation into dumping syndrome after gastrectomy for gastric cancer, [22] many more patients suffer from early dumping syndrome (67.6 %) than from late dumping syndrome (38.4 %) after gastrectomy. This study revealed that patients suffering from at least one symptom of early dumping syndrome were significantly more likely to also experience symptoms of late dumping syndrome. The study also demonstrated that two clinical factors, the surgical procedures used and the amount of weight loss, were significantly associated with the occurrence of both early and late dumping syndromes. Consistent with previous reports, [23, 24] patients who underwent PPG showed the lowest incidence of dumping syndrome. In addition, patients who underwent PG (proximal gastrectomy with jejunal interposition) showed the second highest incidence of early dumping syndrome. Patients who underwent RYGJ showed a lower incidence of dumping syndrome symptoms relative to Billroth I patients. Taken together, RYGJ or Billroth I is less associated with dumping syndrome after distal gastrectomy than Billroth II.

The first step in treating dumping syndrome is the introduction of dietary modification. If this approach is insufficient, medical therapy and, in some cases, surgery might be considered (Fig. 13.2).