Chronic diarrhea, constipation, gas, bloating, and abdominal pain are common symptoms of several disorders of the colon, including irritable bowel syndrome, ulcerative colitis, and Crohn’s disease. But those symptoms also can signal a condition called small intestinal bacterial overgrowth, says Suresh Mahajan, a gastroenterologist on the medical staff of Southwest General.

“Normally there is a lot of bacteria in the colon, or large intestine, but there should be much less in the small intestine,” Dr. Mahajan explains. “Small intestine bacterial overgrowth occurs when an abnormal motility or an alteration in the anatomy of the gastrointestinal tract leads to overgrowth of bacteria in the upper GI tract.”

Here, Dr. Mahajan explains more about small intestinal bacterial disorder.

You may believe, as you carry a bottle of Tums around your office, that your job is giving you an ulcer. That’s probably not true, says Suresh Mahajan, a gastroenterologist on the medical staff of Southwest General. “Mental or emotional stress is not normally a cause of peptic ulcers,” Dr. Mahajan says. “Another misperception is that ulcers are caused by spicy foods. That also is untrue.” In reality, he says, the H.pylori bacterium, and anti-inflammatory medications—like Advil or Motrin—are among the most prominent culprits that cause peptic ulcers. Below, Dr. Mahajan explains more.

Q. What is a peptic ulcer?
A. A peptic ulcer refers to an ulcer, or sore, in the lining of the stomach, or in the lining of the duodenum—the first part of the small intestine. Stomach ulcers also are called gastric ulcers. A peptic ulcer can be superficial, or it can penetrate deep into the lining. Between 5 and 10 percent of people will have an ulcer sometime in their lives, and the risk increases with age.

A lingering sharp pain in your lower left abdominal area could be a symptom of diverticulitis—an inflammation or infection that occurs in the lining of the colon. In the past, surgery often was performed when a patient had as little as two attacks of diverticulitis, says Suresh Mahajan, a gastroenterologist on the medical staff of Southwest General. Today the condition is usually treated by dietary changes and antibiotics. Below, Dr. Mahajan explains more about diverticulitis:

Gluten sensitivity is a common digestive problem. Fortunately, awareness of the problem has increased in recent years. Gluten sensitivity can be painful and uncomfortable, but is it dangerous to your health?It depends, says Dr. Suresh Mahajan, a gastroenterologist on the Medical Staff of Southwest General.

The process of swallowing isn't as simple as you may think. Moving solid food or liquids from your mouth to your stomach requires the coordinated efforts of your throat muscles and your esophagus, explains Dr. Suresh Mahajan, a gastroenterologist on the medical staff of Southwest General. When that process doesn't work as well as it should, it creates a condition called dysphagia. Here, Dr. Mahajan explains what dysphagia is and what you can do about it.

More than half of all adults report having experienced the uncomfortable symptoms of acid reflux at some time in their lives, and about 20% say they have symptoms at least once a week, says Suresh Mahajan, a gastroenterologist on the medical staff of Southwest General.

Dr. Mahajan says reflux, also known as gastroesophageal reflux disease (GERD), occurs when stomach contents escape upwards out of the stomach and into the esophagus, often causing a burning sensation. In the following Q & A, Dr. Mahajan explains more about reflux and what you can do about it.