Just heard back from Minnow's vet. He wants her to come in for surgery.
The x-ray shows a baseball sized lump in her intestine. The vet thinnks it is probably stool, but as it is huge and cement hard it will have to be surgically remove. He also said that giving her a laxitive wouldn't have helped at all, probably would have just given her cramps.
Poor Minnow! I'm glad to know that she will be in good hands tomorrow, but I'm still really worried for her. I am glad though that it isn't likely to be cancer.
I'll post again tommorow afternoon when the vet calls.