Loperamide have negative effects from rebound constipation. If a suspicion exists of diarrhea associated with organisms that can penetrate the intestinal walls, such as or "Salmonella", loperamide is contraindicated as a primary treatment. Loperamide treatment is not used in symptomatic "C. difficile" infections, as it increases the risk of toxin retention and precipitation of toxic megacolon. Loperamide should be administered with caution to people with liver failure due to reduced first-pass metabolism. Additionally, caution should be used when treating people with advanced HIV, as cases of both viral and bacterial toxic megacolon have been reported. If abdominal distension is noted, therapy
Pre-existing condition The University of Pittsburgh Medical Center defines a pre-existing condition as a "medical condition that occurred before a program of health benefits went into effect". J. James Rohack, president of the American Medical Association, has stated on a "Fox News Sunday" interview that exclusions, based upon these conditions, function as a form of "rationing" of health care. Conditions can be broken down into two further categories, according to Lisa Smith of Investopedia: Which definition may be used was sometimes regulated by state laws. Some states required insurance companies to use the objective standard, while others required the prudent person standard.