How old is your hen? When did the symptoms start? Is there tail wagging or straining? Have you tried putting her in a warm bath and using kYgelly (or vaseline in a pich) around the cloacal area after? Separte her and try that if you feed she might be eggbound...if you suspect an egg has broken inside her it would be wise to take her to a vet.
Here is some basic info:
TERMINOLOGY of Common (reproductive) Disorders:
EGG BINDING -Egg binding is defined as failure of an egg to pass through an oviduct at a normal rate. Will often present with straining and a penguin-like stance.
DYSTOCIA -Dystocia is defined as a condition in which a developing egg is in the caudal oviduct and is either obstructing the cloaca or has caused oviductal tissue to prolapse through the oviduct-cloacal opening.
PROLAPSE -Usually the uterus protrudes through the cloaca; often an egg is present. It is important to keep these tissues moist.
SALPINGITIS - infection of the upper reproductive tract. Depression, weight loss, anorexia, and abdominal enlargement can occur with salpingitis.
Metritis is a localized problem within the uterine portion of the oviduct. It can be a result of dystocia, egg binding or chronic oviductal impaction. Bacterial metritis is often secondary to systemic infection. Shell formation and uterine contractions can be affected by metritis. Metritis can also cause egg binding, uterine rupture, peritonitis, and septicemia.
OVIDUCT IMPACTION -This is a condition in which soft-shelled eggs, malformed eggs, or fully formed eggs are stuck in the lower oviduct.
CYSTIC OVA - when an ovarian follicle becomes grossly enlarged and filled with fluid.
OOPHORITIS and OVARY REGRESSION
http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/205810.htm
"Regression of the ovary may result in leakage of free yolk into the abdomen (yolk peritonitis); this rarely causes death except when yolk material migrates through the air sacs to the lung and causes foreign body pneumonia. Free yolk occurs in many cases of acute illness, injury, or forced molt. Regression of the ovary is frequently caused by low body weight, deliberate reduction of feed, overcrowding, or lack of feeder space. Infectious diseases such as exotic Newcastle disease, fowl cholera, pullorum disease, and avian influenza are known to cause this condition. It can also result from severe stress, which is often accompanied by feather molt, emaciation, and dehydration. "
PERITONITIS -Peritonitis can be divided into two categories: Septic and non-septic..... In non-septic peritonitis, egg material without bacteria is free in the abdomen. Acsites may or may not be present. Treatment includes removing the egg material surgically. Septic peritonitis is much worse. It is the most frequent cause of death associated with reproductive disorders. It is most likely not one disease but part of several diseases such as salpingitis, ruptured oviducts....
see further:
http://www.funnyfarmexotics.com/IAS/2003Proceedings/Romagnano_Critical_Ill_hen.pdf
An excellent review of the critically ill eggbound hen
and some treatment measures