A bowel obstruction happens when either your small or large intestine is partly or completely blocked. The blockage prevents food, fluids, and gas from moving through the intestines in the normal way. The blockage may cause severe pain that comes and goes.

This topic covers a blockage caused by tumors, scar tissue, or twisting or narrowing of the intestines. It does not cover ileus, which most commonly happens after surgery on the belly (abdominal surgery).

Tumors, scar tissue (adhesions), or twisting or narrowing of the intestines can cause a bowel obstruction. These are called mechanical obstructions.

In the small intestine, scar tissue is most often the cause. Other causes include hernias and Crohn's disease, which can twist or narrow the intestine, and tumors, which can block the intestine. A blockage also can happen if one part of the intestine folds like a telescope into another part, which is called intussusception.

In the large intestine, cancer is most often the cause. Other causes are severe constipation from a hard mass of stool, and narrowing of the intestine caused by diverticulitis or inflammatory bowel disease.

●Cramping and belly pain that comes and goes. The pain can occur around or below the belly button.

●Vomiting.

●Bloating.

●Constipation and a lack of gas, if the intestine is completely blocked.

●Diarrhea, if the intestine is partly blocked.

Go to hospital right away if your belly pain is severe and constant. This may mean that your intestine's blood supply has been cut off or that you have a hole in your intestine. This is an emergency.

Your doctor may do:

●Check your belly for tenderness and bloating.

●Your symptoms and other digestive problems you've had.

●An abdominal X-ray, which can find blockages in the small and large intestines.

●A CT scan of the belly, which helps your doctor see whether the blockage is partial or complete.

Most bowel obstructions are treated in the hospital.

In the hospital, the doctor will give the patient medicine and fluids through a vein (IV). To help the patient stay comfortable, the doctor may place a tiny tube called a nasogastric (NG) tube through your nose and down into your stomach. The tube removes fluids and gas and helps relieve pain and pressure. The patient will not be given anything to eat or drink.

Most bowel obstructions are partial blockages that get better on their own. Some people may need more treatment. These treatments include using liquids or air (enemas) or small mesh tubes (stents) to open up the blockage.

Surgery is almost always needed when the intestine is completely blocked or when the blood supply is cut off. You may need a colostomy or an ileostomy after surgery. The diseased part of the intestine is removed, and the remaining part is sewn to an opening in the skin. Stool passes out of the body through the opening and collects in a disposable colostomy bag.

If the blockage was caused by another health problem, such as diverticulitis, the blockage may come back if the patient don't treat that health problem.

adhesion [əd'hiːʒ(ə)n] n.粘连

bloating ['blotiŋ] adj.腹胀

blockage ['blɒkidʒ] n.堵塞

colostomy [kə'lɒstəmi] n.结肠造口术

cramping ['kræmpiŋ] n.绞痛

diverticulitis [,daivətikjʊ'laitis] n.憩室炎

enema ['enimə] n.灌肠剂

ileostomy [,ili'ɒstəmi] n.回肠造口术

intussusception [,intəsə'sepʃ(ə)n] n.肠套叠

nasogastric [,neizəu'gæstrik] n.鼻胃管

vomiting ['vɔmitiŋ] v.呕吐

a lack of gas 不排气

bowel obstruction 肠梗阻

get better 好转

scar tissue 瘢痕组织

Ileus is a condition where bowel movement stops for a period of time. It often occurs after surgery on the abdomen. The stomach and the small bowel recover usually within 24 hours after surgery. However, the large intestine takes much longer to recover, sometimes up to 72 hours. This then leads to a backing up of the bowel contents at the level of the colon.

In addition to postoperative causes, ileus also results from intraperitoneal or retroperitoneal inflammation (eg, appendicitis, diverticulitis, perforated duodenal ulcer), retroperitoneal or intra-abdominal hematomas (eg, ruptured abdominal aortic aneurysm, lumbar compression fracture), metabolic disturbances (eg, hypokalemia), or drugs (eg, opioids, anticholinergics, sometimes Ca ²⁺ channel blockers). Ileus sometimes occurs in association with renal or thoracic disease (eg, lower rib fractures, lower lobe pneumonias).

Gastric and colonic motility disturbances after abdominal surgery are common. The small bowel is typically least affected, with motility and absorption returning to normal within hours after surgery. Stomach emptying is usually impaired for about 24 h or more. The colon is often most affected and may remain inactive for 48 to 72 h or more.

Swelling of the bowel, abdominal pain and vomiting of dark bowel contents with a fecal smell are common signs and symptoms of ileus. Blood poisoning (toxemia) and dehydration may also be present. If neglected, ileus can cause shock and pus to form in the infected area (sepsis). Upon examination, the physician will fail to hear the normal bowel sounds in the abdomen. Swollen bowel loops can be seen on X-rays of the abdomen.

Clinical evaluation

Sometimes X-rays

The most essential task is to distinguish ileus from intestinal obstruction. In both conditions, X-rays show gaseous distention of isolated segments of intestine. In postoperative ileus, however, gas may accumulate more in the colon than in the small bowel. Postoperative accumulation of gas in the small bowel often implies development of a complication (eg, obstruction, peritonitis). In other types of ileus, X-ray findings are similar to obstruction; differentiation can be difficult unless clinical features clearly favor one or the other. Water-soluble contrast studies may help differentiate.

Ileus is treated through decompression therapy, which involves providing continuous suctioning through a tube hooked up to a vacuum machine. Food intake is restricted until the bowel sounds reappear and the patient passes gas. The potassium level is monitored as a low potassium level could also contribute to the ileus. Intravenous fluids are given to treat dehydration. When the patient starts to pass gas, their diet is gradually built up from fluids to a full diet over a period of three days.

Treatment involves continuous nasogastric suction, NPO status, IV fluids and electrolytes, a minimal amount of sedatives, and avoidance of opioids and anticholinergic drugs. Maintaining an adequate serum K level (＞ 4 mEq/L [＞ 4 mmol/L]) is especially important. Ileus persisting ＞ 1 week probably has a mechanical obstructive cause, and laparotomy should be considered. Sometimes colonic ileus can be relieved by colonoscopic decompression; rarely, cecostomy is required. Colonoscopic decompression is helpful in treating pseudo-obstruction (Ogilvie syndrome), which consists of apparent obstruction at the splenic flexure, although no cause can be found by contrast enema or colonoscopy for the failure of gas and feces to pass this point. Some clinicians use IV neostigmine.

dehydration [,diːhai'dreiʃən] n.脱水

distention [dis'tenʃən] n.膨胀，扩张

enema ['enimə] n.灌肠剂

hematoma [,hiːmə'təʊmə] n.血肿

intraperitoneal ['intrə,peritəu'niːəl] adj.腹膜内的

obstipation [,ɒbsti'peiʃ(ə)n] n.顽固性便秘

peritonitis [,peritə'naitis] n.腹膜炎

postoperative [pəʊst'ɒpərətiv] adj.术后

retroperitoneal [,rɛtro,pɛritn'iəl] adj.腹膜后的

sepsis ['sepsis] n.败血症

toxemia [tɒk'siːmiə] n.毒血症

bowel loops 肠袢

bowel movement 肠蠕动

bowel sounds 肠鸣音

continuous nasogastric suction 持续胃肠减压

channel blockers 钙离子拮抗剂

decompression therapy 减压疗法

splenic flexure 结肠脾曲