Most of the considerable burden that running places on your musculoskeletal system is absorbed by your legs, where muscles, tendons and ligaments are routinely sore or injured. But your lower abdomen, or suprapubic region, as the site of attachment to the pelvis of many important trunk-stabilizing muscles, can become painful during running as well, either as a result of running itself or through the aggravation of an underlying disorder.
Inflammation of the pubic symphysis, the soft structure in the midline where the left and right pubic bones meet, is called osteitis pubis. Pain and tenderness usually sets in gradually and ranges in quality from dull to sharp. This pain usually is worst in the front and center of the pubic bone, where the symphysis lies, but it may radiate into the inner thighs. Stress overload from training too hard is a major cause, especially in those with biomechanical imbalance such as a leg-length discrepancy. Try taking a break from running, using anti-inflammatories and icing the area; later, strengthening and stretching exercises can help prevent a recurrence.
A sports hernia -- alternatively called Gilmore's groin or athletic pubalgia -- is similar to an intestinal hernia in that abdominal-wall weakness increases susceptibility. However, a sports hernia does not involve protrusion of bowel through the abdominal fascia. In a sports hernia, pain results from a tear where the groin muscles attach to the pelvis. Treatment may involve surgery and the placement of a synthetic mesh, but your healthcare provider will probably first recommend rest, anti-inflammatory drugs, icing the area and possibly physical therapy.
Running is a notorious provocateur of gastrointestinal distress in runners. Mark Jenkins, M.D., of Rice University says that over half of runners and triathletes experience some type of gastrointestinal pain. Flatulence, diarrhea, bloating and cramps can cause pain anywhere in the lower belly and suprapubic region. Dr. Jenkins suggests drinking beverages containing less than 10 percent glucose by volume, since more concentrated drinks are absorbed more slowly and have therefore been implicated in causing gastrointestinal symptoms in runners both in training and in competition.
Cathy Fieseler, M.D., notes that a host of underlying disorders of the pelvis can manifest as suprapubic pain during running. Irritation of the urinary tract and celiac disease can occur in both sexes, and if you're a woman, endometriosis, uterine fibroids, pelvic inflammatory disease secondary to an infection and hormonal changes during the menstrual cycle all need to be ruled out. Dehydration can worsen all of these conditions; anti-inflammatory medications may help with the pain of menstrual cramps.