July 18 (HealthDay News) -- Rates of colitis caused by the bacteria Clostridium difficile among U.S. hospital patients jumped 109 percent between 1993 and 2003, a new study finds.

The study also found that C. difficile colitis became more severe over that time period and caused more deaths among hospital patients.

C. difficile colitis -- which involves an inflammation of the colon -- can cause a variety of symptoms, including severe or complicated diarrhea that can lead to death. Many patients with life-threatening forms of C. difficile colitis have a colectomy (removal of all or part of the colon), an operation associated with high rates of complication and death.

For this study, the researchers analyzed data on more than 78,000,000 patients discharged from U.S. hospitals between 1993 and 2003. Of those patients, almost 300,000 had a diagnosis of C. difficile colitis, a rate of 383 cases per 100,000 discharged patients.

"The rate of C. difficile colitis discharges increased from 261 cases per 100,000 discharged patients to 546 cases per 100,000 discharged patients in 2003, a 109 percent increase," the study authors wrote in the July issue of the journal Archives of Surgery.

The study was led by Dr. Rocco Ricciardi, who was at the University of Minnesota Medical School, Minneapolis, at the time, and is now at the Lahey Clinic in Burlington, Mass.

The colectomy rate among the patients also increased -- from 1.2 per 100,000 patients in 1993 to 3.4 per 100,000 patients in 2003, while the death rate among the patients rose from 20.3 per 100,000 patients in 1993 to 50.2 per 100,000 patients in 2003, a boost of 147 percent.

The study authors believe the rise in C. difficile colitis cases and deaths may be due to new strains of the bacteria that are more resistant to antibiotics and cause more severe illness.

"Heightened awareness of the increasing disease burden of C. difficile colitis is an important first step in controlling the public health ramifications of this important and morbid nosocomial (hospital-acquired) infection," Ricciardi's team concluded.