They have rebound tenderness. I m going to recommend to you that the place to start with these patients is with a plain film series of the abdomen and we ll talk about some of the films. Ultrasound probably has a role in selected instances and CT scanning is beginning to have a bigger role in the evaluation of patients with an acute abdomen but, unfortunately, those are not always available 24 hours a day at every hospital. When you look at an abdomen film, I want you to remember, please, that you have some very inexpensive tools available to you. You can use the air that is Number one, it's like buying a house.
Location is important.
If you remember back to the gross lab, the small bowel is fixed with a mesentery and all of the loops of the small bowel are kind of tethered in the mid abdomen. So if the dilated loops of bowel that you are seeing are centrally located, As opposed to colon, remember that the colon is partially a retroperitoneal structure. It is peripheral in its location. The ascending and descending colons are retroperitoneally fixed and the colon, because it s different than small bowel, has the haustra which are 2-3mm thick, about a centimeter One thing that s important to look at when you re looking at plain films in these patients is to make sure that the technologist gives you a film including the rectum and the sigmoid. Because if you don t see any gas in the rectosigmoid, that should make you think more strongly about the possibility of obstruction.