May 21 (HealthDay News) -- Entereg (alvimopan) has been approved by the U.S. Food and Drug Administration to help restore normal bowel function in people aged 18 and older who have just had bowel resection surgery.

The drug will be restricted to hospital use, and patients are to receive no more than 15 doses, the agency said in a statement. The medication is approved to counter a condition called postoperative ileus (POI), a temporary inability of the bowels to purge waste products. POI can be a side effect of opioid painkillers, such as morphine.

In clinical testing, more people who took Entereg than a placebo suffered a heart attack, although no proof of a "causal relationship" between the drug and heart attack has been established, the FDA said.

Nonetheless, the drug has been approved with a "Risk Evaluation and Mitigation Strategy" to ensure that in each patient, the benefits of the drug outweigh its risks, the agency said.

Common side effects reported during clinical testing included low blood calcium, constipation, heartburn and excess bowel gas.