The symptoms of a bowel obstruction depend on whether the blockage is in the small intestine (small-bowel obstruction) or the large intestine (large-bowel obstruction).
Abdominal pain- Most small-bowel obstructions cause waves of cramping abdominal pain. The pain occurs around the belly button (periumbilical area). If an obstruction goes on for a while, the pain may decrease because the bowel stops contracting. Continuous severe pain in one area can mean that the blockage has cut off the bowel's blood supply. This is called a bowel strangulation and requires emergency treatment.
Vomiting- Small-bowel obstructions usually cause vomiting. The vomit is usually green if the obstruction is in the upper small intestine and brown if it is in the lower small intestine.
Elimination problems- Constipation and inability to pass gas are common signs of a bowel obstruction. However, when the bowel is partially blocked, you may have diarrhea and pass some gas. If you have a complete obstruction, you may have a bowel movement if there is stool below the obstruction.
Bloating- Blockages may cause bloating in the lower abdomen. You may also hear gurgling sounds coming from your belly. With a complete obstruction, your doctor may hear high-pitched sounds when listening with a stethoscope. The sounds decrease as movement of the bowel slows.
Abdominal pain- Blockage of the large intestine usually causes abdominal pain below the belly button. The pain may vary in intensity. Severe, constant pain may mean that your intestine's blood supply has been cut off or that you have a hole in your intestine. This is a medical emergency. Call your doctor immediately.
Bloating- Generalized abdominal bloating usually occurs around the belly button and in the pelvic area.
Diarrhea or constipation. Either of these symptoms may occur, depending on how complete the obstruction is. Your stools may be thin.
Vomiting- This symptom is not common with a large-bowel (colonic) obstruction. If vomiting occurs, it usually happens late in the illness.
Blockages caused by cancer may cause symptoms such as blood in the stool, weakness, weight loss, and lack of appetite.