— Donis, Virginia Persistent back pain, as you describe, is rare with common gastrointestinal disorders like peptic ulcer disease or irritable bowel syndrome (IBS). Ulcers can cause pain, but usually in the front region of the abdomen, known as the epigastrium. When an ulcer is very severe, it can perforate the wall of the duodenum and stomach and cause referred pain to many regions, including the back. However, perforation is a serious complication and would not continue for days or weeks without leading to more severe illness. If perforation is suspected, early imaging and treatment are performed; surgical drainage or resection is often required. IBS leads to bloating and changes in bowel habits (diarrhea, constipation, or alteration between the two), but back pain, while occasionally present in IBS, would not be a characteristic feature. Other gastrointestinal disorders that can cause back pain along with indigestion include pancreatitis and diverticulitis, and I would recommend that you return to your gastroenterologist to get blood tests and imaging tests to test for these relatively common conditions. Q2. I recently read that to attain intestinal relief and to get our immune systems to properly combat germs, our bodies need to have a balance of alkaline and acid. I’m not sure what that means. Can you explain this and recommend some foods? The article said to eat a lot of citrus fruit. — Margaret, Texas Unless the medications you take affect the pH level (a measure of acidity or alkalinity) of your gastrointestinal tract, the stomach is normally very acidic, because of the large amount of acid it produces. This acid can be modestly neutralized by food (flat ginger ale is one of the only foods that is alkaline and neutralizes acid effectively) or by medications that block acid secretion, such as proton pump inhibitors (Prilosec, Prevacid, Aciphex, Protonix, and Nexium) and histamine-receptor blockers (Tagamet, Zantac, and Pepcid). Antacids such as Tums, Mylanta, Maalox, and Gaviscon also help neutralize stomach acid. The normal acid (low pH) environment of the stomach is the body’s first line of defense against harmful organisms that may have been ingested through the mouth, because most organisms are easily killed by the acid. After food passes through the stomach into the small intestine, it’s exposed to a very alkaline (high pH) environment that can destroy any ingested organisms that survive the stomach’s acidity. Some individuals have difficulty with foods that have a higher acid content, such as citrus fruits and tomatoes, because of heartburn or indigestion, but these acids are not as strong as the hydrochloric acid made by the stomach. For this reason, dietary changes have not been shown to change the body’s natural defense system against microorganisms. In summary, you don’t need to worry about eating foods to try to change the pH of your digestive system — your body will do it for you! Learn more in the Everyday Health Digestive Health Center.