Are you a female? Rectoceles can be common in menopausal women, but it's not a requirement, occasionally they occur in men too Rectocele is the wall of the rectum on the other side of the vagina is weakened and has collapsed, but they don't really hurt, so that is probably not it.
There is also
anal fissure, a tear in the rectum due to
constipation, hard stools, and/or straining to have a bowel movement. These can heal on their own, with lots of fiber in food and something like metamucil and a daily stool softener.
There are internal
hemorrhoids, which are also caused by
constipation, as above. They may bleed, and may also heal on their own the same way.
Then there is the possibility of
rectal cancer.
The first three don't involve the abdomen, the last one can. There is no way to even speculate as to the cause of your
abdominal pain. Myriads of possibilities from GYN to colon problems, among others.
It is best to get examined, even though you don't really have the money. Try a county hospital, many work on a sliding scale and charge whatever you are able to pay. Either way, do see someone.
Shannon