It’s a funny name, but if your innards growl, grumble, explode and erupt, you’ve got one irritable bowel.Most people with IBS (10 to 15 percent of the population) have frustrating bouts of cramping, bloating and pain. Some experience constipation, while others have the opposite effect of diarrhea. Still others flip-flop between these two extremes.The gut’s where some of the most intense civil wars are fought. Your body interacts with, processes and reacts to all different nutrients and chemicals. And there are gazillions of foreign bacteria living there, too.People with IBS have some dysfunction of the nervous and immune systems regulating the bowel lining. This lining (the epithelium) regulates the flow of fluids in and out of the intestines. When stuff moves too quickly from start to finish, the intestines can’t absorb the fluid (so it ends up in the toilet). When the last meal moves too slowly, the bowel absorbs too much fluid so it stays in our system.The second aspect of IBS involves the neurotransmitter serotonin. It’s found primarily in your gut, and only a small amount in your brain. People with IBS have abnormally low serotonin levels. This causes digestive problems and makes people more susceptible to feeling pain when those problems arise.Even if you have exactly the same amount of gas as the next gal, you’ll sense more pain if your serotonin’s low. The same stress that everyone feels will cause you depression, if your brain serotonin levels are low. (IBS is not acid reflux, by the way. To treat that, elevate your head at night and be careful to not eat acidic food too late.)QUIZ: What’s Your Eating Style?Potential culprits for spastic colon and IBS are hidden infections that we historically haven’t been checked for. Doctors look for two main ailments:SIBO (Small Intestinal Bacterial Overgrowth): The small intestine gets the first shot at digesting food and shouldn’t have as many bacteria as the colon (large intestine). If your bowels are sluggish, the bacteria can move upstream to the small intestine, causing irritable bowel symptoms.Doctors use a hydrogen breath test (HBT) to look for SIBO. If it’s positive, an antibiotic like rifaximin (400 mg a day for seven to 10 days) will likely eliminate the spastic bowel. If the sluggish bowel isn’t treated, it can come back. A low thyroid (despite normal lab results) is a cause of SIBO, with as many as half of those with a low thyroid having a positive HBT.Yeast Overgrowth: Although still controversial, many holistic docs believe that treating yeast overgrowth in the gut will eliminate spastic colon and sinusitis (the yeast causes swelling in the nose).Watch Your Diet: If your gut twists and turns like an amusement park, try eating food that can calm the digestive process. With IBS, eliminate high-fat or fried foods, alcohol, caffeine, carbonated drinks and gum (swallowing air only makes things worse).WATCH VIDEO: Why We Have GasSubstitute foods that are high in fiber. Eat slowly and regularly, avoiding the highs and lows that come from overeating and starving. You can ID trigger foods by keeping an eating diary that pinpoints your feel-better and feel-worse patterns.Many people with spastic colon have trouble digesting sugar and milk (lactose intolerance). You can test for this problem, but it could be easier to avoid all sugar (sodas) and milk for a week and see if the symptoms subside.Probiotics are your best dietary allies. The best are in spore form so the stomach doesn’t destroy them. Get small capsules at less than $10 a month. Some believe a lack of good bacteria in the intestines is the cause.Sorry if this sounds like a broken record, but keep trying omega-3s (2 gm a day of fish oils or 400 mg of algal DHA). Oh, and don’t forget 1,200 to 2,000 IU of vitamin D3 a day.MORE: Eat to Beat Abdominal Distress