The presenting complaint in a patient with intestinal obstruction will usually demonstrate, pain, vomiting, abdominal distension and constipation. Indeed, any patient presenting with these four symptoms should be suspected of having intestinal obstruction.
However, a patient with obstruction may not exhibit all of these symptoms so their absence does not rule out obstruction. For instance, distension may be minimal if the obstruction is proximal. The patient may only pass a bowel motion once every three days so one may have to wait for three days to see if there are no bowel motions. Many patients with obstruction complain of little pain.
If the patient does have pain, it is typically intermittent, the frequency of the colic depends on the site of the obstruction. Continuous pain should suggest an alternative diagnosis or a complication of obstruction such as perforation. Proximal obstruction gives more frequent pain than distal obstruction. Colic from the proximal small bowel occurs every 10 minutes or so while that from the colon may occur once every few hours. Whatever the frequency of the pain, it is typically felt in the midline and does not have a pin point localisation. Colic from the fore-gut is felt in the epi-gastrium, that from the mid and hind guts in the peri-umbilical and hypo-gastric regions respectively.
Pain in intestinal obstruction does not usually radiate. The pain is or the `visceral' type and is not well localised, but it is felt to the front of the abdomen and in the midline. The bouts of colic are quite uncomfortable but usually not as severe as say biliary colic or renal colic. The onset is typically gradual, a sudden onset suggests torsion of an ovary or perforation of the intestine. The colic comes and goes on its own. It may seem to be relieved by vomiting. The patient wants to stay still when he/she has the colic but, they will also try to move about to see if it relieves it. Movement does not aggravate the colic.
It is wise to ask the patient about their general health in the last few months. Has there been, weight loss, loss of energy, loss of appetite. This may indicate the presence of an underlying malignancy. Similarly, enquire about blood PR as this may indicate a malignancy.