The signs and symptoms of small bowel obstruction include the following:

• Intermittent cramps in the abdomen
• Nausea accompanied by vomiting
• Bouts of constipation and diarrhea
• Abdominal distention
• Bad breath 
• Excessive gas and inability to pass out the same

• Collapse

  The collapsed cecum and sigmoid colon should be noted (arrows). A specific point of obstruction (transition point) cannot always be seen on CT, but the dilated proximal bowel and collapsed distal bowel are highly suggestive of the diagnosis. [msdmanuals.com]

  The last image shows the collapsed rectum posterior to the dilated small bowel loops. In the pelvis dilated small bowel loops were seen and a collapsed distal sigmoid (arrow). [radiologyassistant.nl]

  He underwent abdominal computed tomography (CT), which showed a sudden change of diameter in the distal ileum with complete collapse of the proximal small bowel segment. [ncbi.nlm.nih.gov]

  Note the collapsed bowel loops (arrow) distal to the obstruction point. [pubs.rsna.org]

  Proximal bowel dialation with distal bowel collapse - proximal small bowel dilated more than >2.5cm. Gasless abdomen CT abdomen: provides more information than plain films. [aci.health.nsw.gov.au]

• Anemia

  Bezoar formation has even been observed in case of reduced gastric motility and secretion due to diabetes, hypothyroidism, pernicious anemia, myotonic syndromes, and Guillain-Barré syndrome. [ncbi.nlm.nih.gov]

  Right-sided lesions usually manifest with bleeding and anemia; left-sided lesions usually manifest with obstructive symptoms (eg, colicky abdominal pain). [merckmanuals.com]

  Obstruction, intestine) 560.9 intestine (see also Obstruction, intestine) 560.9 rectosigmoid (see also Obstruction, intestine) 560.9 sigmoid (see also Obstruction, intestine) 560.9 Enterostenosis (see also Obstruction, intestine) 560.9 Gangrene, gangrenous (anemia [icd9data.com]

  Anemia may be a sign of intra-abdominal hemorrhage (e.g., in postoperative or trauma patients). [amboss.com]

  In-hospital mortality in patients who underwent emergency gastrointestinal (GI) surgery was associated with cancer-related peritonitis, preoperative anemia, and preoperative hypoalbuminemia [8]. [hindawi.com]

• Fatigue

  The most common side effects reported with therapy are temporary tenderness, aching, fatigue and hip or back pain. When they occur, these symptoms pass within a few days. Improvements in other areas of the body. [clearpassage.com]

  Fatigue and weakness caused by severe anemia may be the only complaints. Tumors sometimes grow large enough to be palpable through the abdominal wall before other symptoms appear. [merckmanuals.com]

• Lymphadenopathy

  CTscans of 11 patients with small bowel lymphoma were separately analysed in terms of affected section of the small bowel, focality, wall thickness, pattern and degree of contrast enhancement, lymphadenopathy, organ involvement, perforation, and the presence [ncbi.nlm.nih.gov]

• Vomiting

  The classic symptoms of nausea, vomiting, abdominal pain, and constipation are rarely present in all cases of SBO. Abdominal pain associated with SBO is often described as crampy and intermittent. [emedicine.medscape.com]

  Classic Presentation History The patient with a small bowel obstruction will usually present with abdominal pain, abdominal distension, vomiting, and inability to pass flatus. In a proximal obstruction nausea and vomiting are more prevalent. [saem.org]

  The boy presented with a 3-day history of repeated bouts of abdominal pain and vomiting, which became bilious on the last day. Abdominal US examination showed four rounded anechoic masses in the small bowel. [ncbi.nlm.nih.gov]

• Abdominal Pain

  A 54-year-old postmenopausal woman presented with severe abdominal pain and vomiting. Before menopause, she sometimes had abdominal pain associated with menses. [ncbi.nlm.nih.gov]

  On HOD4, the patient developed nausea/vomiting and abdominal pain, a nasogastric tube was placed with feculent output. [ddxof.com]

• Constipation

  CASE: A 29-year-old woman presented to the emergency department with abdominal pain, constipation, nausea, and vomiting. CT scan revealed dilated loops of small bowel suggestive of SBO and an IUD that did not appear within the uterine cavity. [ncbi.nlm.nih.gov]

  […] affects bladder control Constipation can cause accidential leakage from your bladder. [continence.org.au]

  The classic symptoms of nausea, vomiting, abdominal pain, and constipation are rarely present in all cases of SBO. Abdominal pain associated with SBO is often described as crampy and intermittent. [emedicine.medscape.com]

• Nausea

  We present the case of a 61-year-old man with no previous surgery who presented with central abdominal pain, nausea and vomiting. An abdominal CT scan demonstrated SBO with a transition point in the left anterior abdomen. [ncbi.nlm.nih.gov]

  Step 1: Pathway Entry Symptoms to consider: Abdominal pain, bloating, nausea, vomiting, inability to pass flatus or stool Signs to consider: Abdominal distension, abdominal tenderness, peritonitis, hyperactive and high pitched bowel sounds, presence of [aci.health.nsw.gov.au]

  These may be needed to ease pain, nausea, and other symptoms. They may also be needed to treat or prevent infections. A soft, thin, flexible tube (nasogastric tube) is inserted through your nose and into your stomach. [saintlukeskc.org]

• Abdominal Distension

  Alert the provider immediately to any increase in pain, nausea, or abdominal distension. Keep the head of the bed elevated to help prevent aspiration and to improve respiratory status. [journals.lww.com]

  Abdominal distension? 2. What is the sensitivity and specificity of imaging modalities for small bowel obstruction? 2a. A normal abdominal X-ray? 2b. Air fluid levels seen on abdominal X-ray 2c. CT findings. 3. [sinaiem.org]

• Oliguria

  Shock and oliguria are serious signs that indicate either late simple obstruction or strangulation. Obstruction of the large bowel usually causes milder symptoms that develop more gradually than those caused by small-bowel obstruction. [merckmanuals.com]

  Investigations Fluid charts are required to monitor intake and output, especially as an intravenous infusion is almost certainly required, a nasogastric tube may be passed and oliguria is an important sign of early dehydration. [patient.info]

Prompt diagnosis of the condition is required in order to prevent complications from setting in. A physical examination will be performed to hear out the bowel sounds from the stomach. No bowel sounds indicate paralytic ileus. On the other hand, if very hyperactive bowel sounds are heard they are indicative of mechanical obstruction.

In addition to physical examination, various imaging studies such as CT scan [4], MRI, radiography and X-ray will be carried out to study the abdominal structures and confirm diagnosis. Contrast enhanced abdominal CT may reveal the small bowel feces sign indicative of low grade partial obstruction that could still be managed conservatively [5].

A complete blood work also has to be carried out to study blood urea nitrogen, white blood cells count, and hematocrit. Urine analysis and lactose dehydrogenase tests are also done. It is important to rule out certain underlying disease conditions such as biliary or hepatic disease and therefore several tests governing these also have to be carried out.

• Pneumoperitoneum

  […] should be, at the beginning, conservative except that cases that presents clinical and/or CT-scan findings predictive for a surgical treatment (free peritoneal fluid, mesenterial edema, transitional point) or a peritonitis (pneumatosis intestinalis, pneumoperitoneum [ncbi.nlm.nih.gov]

  In other hands, many patients have co-morbidities, and consequently it is key to work with a low intra-abdominal pressure to prevent any conversion for pneumoperitoneum intolerance. [websurg.com]

  The MDCT findings of bowel ischaemia or perforation included: (1) decreased bowel wall enhancement, (2) pneumatosis intestinalis, (3) portal venous gas, and (4) bowel wall perforation with pneumoperitoneum. [journals.plos.org]

  A large volume pneumoperitoneum secondary to bowel perforation in ASBO can also be detected on plain X-rays, preferably by an erect chest X-ray. Plain X-rays, however, do not detect the more early signs of peritonitis or strangulation [59,60,61]. [wjes.biomedcentral.com]

• Bowel Distention

  Abdominal X-Ray Small bowel distention Nasogastric tube is seen coiled in the gastric fundus CT Head Left occipital extracranial soft tissue hematoma Left occipital epidural hematoma subjacent to the fracture site in addition to subarachnoid hemorrhage [ddxof.com]

  […] palpable Abdominal Distention and tympany on percussion Indicates distal obstruction Abdominal Distention has greatest PPV Rectal examination for blood IX. [fpnotebook.com]

  Obstipation or constipation Abdominal distention High-pitched, tinkling bowel sounds (early) Absent bowel sounds (late) Diffuse, continuous abdominal pain Vomiting Obstipation or constipation Marked abdominal distention Tympany on percussion Absent bowel [amboss.com]

  There is also distention of the small bowel diameter to more than 2.5 cm and a small bowel–colon diameter ratio of greater than 0.5. [pubs.rsna.org]

• X-Ray Abnormal

  Home » Tutorials » Abdominal X-ray Tutorials » Abdominal X-ray - Abnormal bowel gas pattern » Introduction » 1 2 3 4 5 6 » Conclusion Key points Dilated small bowel >3cm is considered abnormal Small bowel obstruction and ileus can have similar appearances [radiologymasterclass.co.uk]

• Hyponatremia

  However, hyponatremia (≤134 mmol/L) and CT scan findings of wall thickening or a suspected closed loop were independently associated with bowel ischemia. [ncbi.nlm.nih.gov]

  Laboratory tests If recurrent vomiting Hypochloremic hypokalemic metabolic alkalosis Hyponatremia If bowel strangulation Metabolic acidosis Hyperkalemia Neutrophilic leukocytosis (left shift) If dehydration: ↑ Hct If sepsis: abnormal coagulation profile [amboss.com]

• Hyperglycemia

  […] disturbances (these may irritate both the stomach and the parts of the brain that coordinate vomiting):[citation needed] Hypercalcemia (high calcium levels) Uremia (urea accumulation, usually due to kidney failure) Adrenal insufficiency Hypoglycemia Hyperglycemia [en.wikipedia.org]

• Leukocytosis

  The abdominal tube drained a small amount of serous fluid, while blood tests revealed a mild leukocytosis and a slight decrease of the hemoglobin. [ncbi.nlm.nih.gov]

Treatment of small bowel obstruction is geared towards the nature and type of obstruction. Patients with no signs of strangulation and vomiting supported with the characteristic signs of partial small bowel obstruction may be managed medically [6].

Non-operative patients may be managed by adequate fluid resuscitation and naso-gastric drainage which can help patients to recover spontaneously within 72 hours in a majority of cases [7]. Medications however form the primary basis of the treatment regime and surgery may have to be opted for when the situation gets severe.

Whichever be the case, hospitalization would be required in order to stabilize the patient’s condition, after which treatment would be initiated. The following are the modes carried out for treating small bowel obstruction:

• The patient is put on intravenous fluids to replace the fluid loss.
• A tube is inserted either through the nose or mouth in order to expel the gas buildup in the abdomen.
• Hyperbaric oxygen introduction to the small bowel may relieve low grade forms of small bowel obstruction [8].
• Surgery may be required when the affected part of the intestine has died. In such cases, the diseased portion of the intestine part is removed and the two healthy ends are joined. Laparoscopic may offer a safer alternative option in some cases of small bowel obstruction [9]. The role of the small intestine decompression tube with gastrografin in the surgical management of the inflammatory small bowel obstruction has reduced the incidence or unnecessary re-operations [10]. 

The prognosis is usually good if diagnosis is made on time and prompt treatment is carried out. If cases of complete obstructions are treated with medications, then the patients fully recover but the chances of recurrence of the obstruction are higher than those treated with surgery.

Partial obstructions are successfully treated with medications and the chances of recurrence are low. Morbidity and mortality profile of the disease depends on how soon the diagnosis was made and treatment initiated.

It has been estimated that if the obstructions are left untreated then it causes death in 100% of cases. If the surgery is performed within 36 hours then the mortality rate is as low as 8%. However, if the surgery is postponed beyond 36 hours, then the mortality rate rises to 25%.

Complications

Untreated small bowel obstruction can present the following life threatening complications:

• Peritonitis characterized by infection of abdominal cavity.
• Tissue death characterized by lack of blood supply (ischemia) to the walls of intestine [3]
• Aspiration 
• Wound dehiscence
• Short bowel syndrome
• Death 

Small bowel obstruction can be mechanical or non-mechanical in nature. In the mechanical type, some foreign body blocks the passage of intestinal contents making it difficult for its passage through the intestine.

In the latter type, there is no mechanical obstruction, but non–functioning small intestine does not allow the contents to move through the digestive system.

Non–mechanical obstruction is also known as paralytic ileus or pseudoobstruction. Children and infants are common victims of such type of obstruction.

The causes of mechanical obstruction have been explained below:

• Abdominal surgery that has not healed properly and has caused scars inside the tissues contributing to obstruction like uterine perforation [1]
• Intussusception
• Volvulus
• Foreign bodies from certain objects or items that were swallowed and got stuck
• Colon cancer
• Diseases such as Crohn’s disease and Parkinson’s disease
• Strangulated hernia
• Persistent vestigial structure like the omphalomesenteric duct in children [2] 

Small bowel obstruction is a common phenomenon with abdominal surgery being the root cause for majority of the cases. Statistics reveal that as high as 300,000 laparotomies every year were carried out to treat small bowel obstruction. Males and females are at an equal risk for contracting this disease condition.

Small bowel obstruction can be partial or complete; with the complete one being a life threatening condition. Under normal circumstances, the small intestine carries out the function of absorption of nutrients from the food that is digested.

When there is an obstruction, there is proximal dilation of the intestine due to buildup of stomach contents and fluid. The dilation further stimulates the cell secretion activity which leads to buildup of more fluid. This is in turn causes peristalsis above and below the area of obstruction resulting in loose motions and flatulence in the preliminary stages. If the obstruction is in the proximal levels then individuals experience vomiting.

So far no guidelines have been issued to prevent this disease condition. However, it is suggested that underlying disease conditions should be promptly treated in order to avoid the onset of small bowel obstruction as a secondary complication to other diseases.

Small bowel obstruction (SBO), a type of intestinal obstruction, is a blockage in the small intestine that prevents the passage of the intestinal contents. This leads to accumulation of stool, fluid and gas inside the intestine causing discomfort.

The obstruction can be either partial or complete. If urgent medical attention is not provided then the condition can turn life threatening. In certain cases, medications for 2 to 5 days can do the job; whereas in some other cases, surgical procedures have to be employed to remove the obstacle.

Definition

Obstruction occurring in the small intestine which prevents the emptying of the stomach contents is defined as small bowel obstruction. Obstruction can either be partial or complete in nature. There are 2 types of obstruction; namely mechanical and non–mechanical. Mechanical obstruction occurs due to obstruction usually created by foreign particles that have been swallowed. Non–mechanical obstruction is the result of a non - functional small intestine, a condition also known as paralytic ileus.

Cause

Causes of small bowel obstruction include scars due to certain operative procedure, volvulus, intussusceptions, and foreign bodies.

Symptoms

Symptoms of small bowel obstruction include nausea accompanied by vomiting, abdominal cramps, abdominal distention, constipation, diarrhea, flatulence and bad breath.

Diagnosis

Diagnosis of the disease includes a physical examination geared towards studying the bowel sounds. In addition, imaging studies such as CT scan, MRI, and X- ray also may have to be carried out to study the intestinal structures. Blood work to test presence of underlying disease condition and also to study the hemoglobin, white blood cells and blood urea nitrogen also needs to be done.

Treatment

Treatment of small bowel obstruction requires hospitalization following administration of intravenous fluids to compensate for the fluid loss. Post this, a tube is inserted through the mouth or nose in order to expel out the accumulated gas. Surgical procedures may be required in severe cases.

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9. Khaikin M, Schneidereit N, Cera S, Sands D, Efron J, Weiss EG, et al. Laparoscopic vs. open surgery for acute adhesive small-bowel obstruction: patients' outcome and cost-effectiveness. Surg Endosc. May 2007; 21(5):742-6.
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