The blood into the bowel every day

A huge amount of water–7 to 9 L–moves from the blood into the bowel every day, through osmosis and digestive secretions. Since people only have 5 L of blood, why don’t they die from losing all the water from their blood into the bowel? What will the water do then?
If the small intestine is obstructed, food cannot move along it and be absorbed into the blood. This is what has happened to Mrs. M. How did that cause her blood pressure to drop? AID a link diagram that shows the water movement involved.
You get the results of Mrs. M’s blood tests and see that everything is out of balance! The concentrations of everything in her blood are higher than usual. Is this a consequence of her intestinal obstruction, or is something else happening?.
The ER physician has ordered intravenous fluid replacement to bring Mrs. M’s blood volume back up. What might his reasoning be?
After treatment with intravenous fluids, Mrs M. is feeling better and is able to talk with her doctor. She tells you she has finally agreed to have a colostomy. She refused this operation for years because her aunt had an ileostomy and struggled with fluid balance and managing her ileostomy bag. She asks you about water balance and why fluid balance was a problem for her aunt. Explain why her aunt’s fluid balance issues.
In Mrs. M’s aunt’s ileostomy, all of the large intestine was removed. In a colostomy, only part of the large intestine is removed. How will water balance be different in patients with an ileostomy versus a colostomy?