The children of Iraq are facing a health crisis from the combined effects of war, 12 years of international sanctions and post-war instability. A major outbreak of diarrhea has hospital wards under severe pressure.

A tiny child wails in pain and fear after a nurse examines her in the emergency room of Baghdad's Central Teaching Hospital for Children. She is one of the 750 to 1,000 children the hospital will treat today, roughly 80 percent of them suffering from severe or acute diarrhea.

Mustafa, 4, is already occupying one of the beds in the emergency ward. His father says he was perfectly healthy just two days ago. But then he came down with diarrhea and started vomiting blood. Now he lies unconscious in the hospital bed.

Mustafa's father asks the doctor why his son's condition has deteriorated so badly. He says he is afraid because his son has gotten so ill, so quickly.

Dr. Mohammed Hassan says the hospital is running tests on the child, but he suspects the cause of the boy's illness is very toxic water-borne bacteria.

He asks the father where he gets his water for his family. The father says he gets the water from the Tigris river, and then he tries to boil it before he gives it to the children.

Dr. Hassan says this is not unusual. He blames the city's poor water supply for most of the cases of diarrhea he sees every day.

"Many children who are successfully treated at the hospital with available medicine and equipment, later return with similar causes of diarrhea," he said. "That reflects that the sterility of the water is not the problem of the hospital, it is the problem of the city."

Diarrhea was a major killer of children in Iraq even before the war, but health experts believe the problem is worse now.

The Baghdad water supply system has been battered from all sides. It was in bad shape before the war, and it took a pounding during the sustained bombardment of Baghdad, even though coalition forces made a concerted effort to avoid hitting humanitarian infrastructure.

Since then, the water system has been hit by both sabotage and looting, which UNICEF representative Carel de Rooy says have done more damage than the war itself.

"The state of the distribution systems has deteriorated further, compared to the situation before the war. And that contaminates the water because you have leaks all over," she said. "There is cross-contamination with sewage ? which renders the water quality very low. And that, not just reduced quantity of water, but deteriorating quality of water, is at the root of the diarrhea today in Iraq."

Coalition forces say insurgents have targeted the Baghdad electricity and water systems in an effort to undermine the coalition authority in Iraq. But not all of the acts of sabotage are done with ill intent. Some families desperate for water poke holes in the pipes to get water out.

Diarrhea is not the only health problem facing children in Iraq today. World Health Organization spokeswoman Fadela Chaib says WHO is very concerned about a rise in vaccine-preventable diseases such as whooping cough, measles, and diphtheria.

"For example, in the south we have more than 30 cases of whooping cough, which is a disease mainly of children," she said. "And we are wondering, why do we have these cases? Is this because there is a failure somewhere of vaccination, or it is related to power cuts, that the vaccines are no longer active? So this is a concern for WHO, and we are investigating."

U.N. and coalition officials believe they are making progress in repairing the infrastructure in Baghdad. UNICEF has made more than a thousand repairs to the Baghdad water system, but U.N. officials say the supplies of water to residents is still shrinking.

Residents continue to be frustrated by the slow pace of improvement.

The arrival of summer has intensified the situation. Temperatures are approaching 50 degrees Celsius, and dehydration is a constant danger, especially for children.

In the diarrhea ward at the hospital, Nabil Khalaf cradles her unconscious four-month-old daughter Mariam in her lap. Mariam has had diarrhea for the past month, and Mrs. Khalaf says her extended hospital stay has made things even harder for their family.

She says she thought things would get better after the war, but they have gotten worse. There is even less water available, and her husband no longer has a job or an income. She says the hospital is not free.

Until the water distribution system can be fixed, UNICEF is importing roughly three million liters of water a day from Kuwait, bringing it to southern Iraq in huge tanker trucks. Another two million liters is going to impoverished neighborhoods in Baghdad.

The agency hopes that will help keep families from having to go to the river for water, and therefore help keep their children healthy.