U.S. military officials say Islamic State foreign fighters are losing morale and making excuses not to fight, and a recent stash of records left behind by its fighters in Mosul appears to confirm that.

One Belgian militant had a medical note saying he had “back pain” and would not join the battle, according to the documents reported by the Washington Post.

Another foreign fighter from Kosovo said he had “head pain.” He and another Kosovar asked to move to Syria.

Another from France said he wanted to leave Iraq to carry out a suicide attack at home, several requested transfers to Syria, and some just refused to fight.

The stashes were found by Iraqi forces after they took over an ISIS base in Mosul, the terrorists’ embattled stronghold in Iraq.

“There are fighters who don’t want to fight or who are making excuses and want to leave the country, [the records] are indicators that are useful to us and they provide some insight into the state of the enemy,” the spokesman for the U.S.-led coalition Air Force Col. John Dorrian told reporters at the Pentagon on Wednesday.

Since October, Iraqi forces supported by a U.S.-led coalition have begun pushing ISIS out of Mosul, and U.S. officials say its members still left in Western Mosul now face two choices.

“They’re either going to surrender or they’re going to be annihilated,” Dorrian said.

“They are on the back foot. Their fighters are being killed very quickly in some cases. And they are completely isolated in west Mosul, and they’re awaiting their fate there,” he said.

As recently as last year, ISIS was still attracting about 2,000 foreign fighters per month to Iraq and Syria, but now the numbers are down to between 100 to 200, Dorrian said.

The records have also prompted concerns that some fighters are indeed making their way back home. Of more than 4,000 foreign fighters who have left the European Union nations, about one third have returned home, according to a report by the International Centre for Counterterrorism.

Dorrian acknowledged that there are “small numbers” of ISIS fighters getting out of Iraq and Syria.

“It’s small numbers. They’re not — not really in any position to be leaving because, in many areas, they’re isolated,” he said.

“He doesn’t want to fight, wants to return to France,” said the records on one 24-year-old French resident of Algerian descent. “Claims his will is a martyrdom operation in France. Claims sick but doesn’t have a medical report.”

At one ISIS base, five out of 14 records belonged to French citizens. At another, 16 Russian and four French passports were found. There were also 20 blank Iraqi passports, suggesting that militants were forging them to leave the country.

More foreign fighters have come from France than any other country in Europe since 2011, when the Syrian civil war began, fueling the rise of ISIS. The French government said 700 of its citizens joining ISIS remain in Iraq and Syria, including 275 women and 17 minors, according to the Post.

Terrorism expert Aymenn al-Timimi told the paper, “There are plenty of foreign fighters that went and found that the ISIS experience wasn’t what they thought it would be.”

“They thought it would be a great adventure,” he said.