The usual presenting complain is pain and bloating. This pain is often mild and vague initially but is later described as cramps. They may also present with poor appetite, nausea and vomiting. Patients could also present with inability to pass faeces or flatus but this is not common in all patients. There is abdominal distension and the degree will depend in the level of the ileus. The abdomen will also be tympanic to percussion and there may be some degree of tenderness. A distinctive feature of ileus is the reduced or complete absence of bowel sounds on auscultation which is usually referred to as the silent abdomen [6].

• Pain

  One group of drugs that shows promise for treating abdominal pain is a class of medications known as kappa-opioid agonists. As of 2004, however, these drugs are still under investigation for controlling visceral pain in humans. [medical-dictionary.thefreedictionary.com]

  […] need to log in. il·e·us | \ ˈi-lē-əs \ : obstruction of the bowel especially : functional obstruction of the gastrointestinal tract and especially the small intestine that is marked by the absence of peristalsis, is usually accompanied by abdominal pain [merriam-webster.com]

  Interventions • Interventions Notify surgeon of changes in: o VS o Bowel sounds o Decreased urine output o Increased abdominal distention o Pain Maintain strict I&O record Monitor for signs of dehydration and electrolyte imbalance Assess pain and provide [slideshare.net]

• Inflammation

  […] and peritonitis retroperitoneal hematoma acute mesenteric ischemia: ileus limited to a vascular territory 10 The cause of ileus is thought to be complex and multifactorial, involving bowel inflammation 6, inhibitory neural reflexes 7, and neurohormonal [radiopaedia.org]

  If the gallstone dislodges, the inflammation can clear up. [osmosis.org]

  It also can result from certain drugs, spinal injuries, inflammation anywhere within the abdomen that touches the intestines, and diseases of the intestinal muscles themselves. [medicinenet.com]

  He said questions still remain about the differences between healthy and diseased tissue behavior, inflammation’s role in the disorder, and lidocaine’s effects on postoperative ileus. [thehorse.com]

• Sepsis

  In general, symptoms of abdominal sepsis include fever, tachycardia, and tachyphemia. Sepsis related to gram-negative bacteria can present with hypotension, hypothermia, and bradycardia. [nursingcenter.com]

  It usually occurs in response to physiological stress, including surgery, sepsis, metabolic derangements, and Gl diseases. [bestpractice.bmj.com]

  In the dynamic class would fall those cases due to peritonitis, trauma, sepsis, reflex irritations, spinal lesions, etc. But even in the Full Text [jamanetwork.com]

  Paralytic ileus may also be caused by peritonitis; ischemia or surgical manipulation of the bowel; retroperitoneal hemorrhage; spinal fracture; systemic sepsis; shock; hypokalemia; uremia; pharmacologic agents (eg, vincristine, loperamide, and calcium [patientcareonline.com]

• Falling

  In the dynamic class would fall those cases due to peritonitis, trauma, sepsis, reflex irritations, spinal lesions, etc. But even in the Full Text [jamanetwork.com]

  The terminology used to describe postoperative ileus falls into two distinct classifications. [news-medical.net]

  The thin tapes over the incision (called STERI-STRIPS) will fall off on their own. Your child can have a tub bath one week after surgery. [chop.edu]

• Acutely Ill Patient

  Films taken in the upright position (standing or sitting in acutely ill patients) or when lying on the side (the most sensitive view) may demonstrate free intraperitoneal air, which is evidence of GI perforation (Figure 6.1-16). [empendium.com]

  Suk-Kyung Hong, How to Feed Critically Ill Patients, JOURNAL OF ACUTE CARE SURGERY, 5, 1, (1), (2015). [doi.org]

• Pneumonia

  This case occurred in a 19-year-old man with small bowel 'ileus' following Klebsiella pneumonia. [helloenglish.com]

  ‘This case occurred in a 19-year-old man with small bowel ileus following Klebsiella pneumonia.’ [en.oxforddictionaries.com]

  Infections, such as: Abdominal infections: peritonitis, appendicitis, diverticulitis and Pneumonia. Heart attack. Imbalance of electrolytes. Disorders that affect muscle function. [stomawise.co.uk]

  Finally, basing on clinical and radiological studies, pneumonia was diagnosed as a cause of patient’s state and antibiotic treatment with cefotaxime was started. [journals.viamedica.pl]

  Other secondary causes may include pneumonia, pancreatitis, or urinary tract infection. Primary issues are related to surgery or opioid treatment and can occur after an extended case with a lengthy lysis of adhesions and prolonged case length. [medpagetoday.com]

• Dyspnea

  Two years prior to admission he had noticed the onset of intermittent claudication, occasional nosebleeds, dyspnea on effort, orthopnea, and occasional angina. At one time he experienced a sudden coldness of his left leg lasting several hours. [annals.org]

  Case report In April 2010, a 64-year-old Caucasian man arrived at the hospital with a six-day history of bilateral lower-extremity edema, right upper-extremity edema, shortness of breath, paroxysmal nocturnal dyspnea, and orthopnea. [academic.oup.com]

• Vomiting

  While there was no difference in the frequency of postoperative nausea and vomiting between the 2 groups (P = .3), the actual vomiting occurred less frequently in colloid group (P = .02). [ncbi.nlm.nih.gov]

  Retrieved January 14th, 2019, from https://www.yourdictionary.com/ileus ileus noun Intestinal obstruction causing colic, vomiting, and constipation. [yourdictionary.com]

  Severe vomiting is rare, but if it occurs, the buildup of gas and liquid caused by ileus must be relieved. [merckmanuals.com]

  There is persistent vomiting and abdominal distention. [medical-dictionary.thefreedictionary.com]

  […] obstruction of the bowel especially : functional obstruction of the gastrointestinal tract and especially the small intestine that is marked by the absence of peristalsis, is usually accompanied by abdominal pain, bloating, and sometimes nausea and vomiting [merriam-webster.com]

• Nausea

  ˈi-lē-əs \ : obstruction of the bowel especially : functional obstruction of the gastrointestinal tract and especially the small intestine that is marked by the absence of peristalsis, is usually accompanied by abdominal pain, bloating, and sometimes nausea [merriam-webster.com]

  However, side effects include postoperative nausea and vomiting, shivering, ileus, and urine retention and are specifically discussed here. [ncbi.nlm.nih.gov]

  Symptoms are nausea, vomiting, and vague abdominal discomfort. Diagnosis is based on x-ray findings and clinical impression. Treatment is supportive, with nasogastric suction and IV fluids. [merckmanuals.com]

• Constipation

  Risk factors for constipation in the ICU According to Nassar et al, (2009), constipation occurred in 69.9% of the patients who stayed for loger than 3 days in the ICU. [derangedphysiology.com]

  Retrieved January 14th, 2019, from https://www.yourdictionary.com/ileus ileus noun Intestinal obstruction causing colic, vomiting, and constipation. [yourdictionary.com]

  CONTINUE SCROLLING OR CLICK HERE FOR RELATED SLIDESHOW SLIDESHOW Super Tips to Boost Digestive Health: Bloating, Constipation, and More See Slideshow [medicinenet.com]

  The symptoms of ileus are abdominal bloating caused by a buildup of gas and liquids, nausea, vomiting, severe constipation, loss of appetite, and cramps. People may pass watery stool. [merckmanuals.com]

  Nonselective μ-opioid receptor antagonists reverse constipation and opioid-induced ileus but cross the blood-brain barrier and may reverse analgesia. [ncbi.nlm.nih.gov]

• Abdominal Pain

  EBM Guidelines Jul 20, 2018 • Latest change Mar 28, 2017 Table of contents Search terms Abdomen, Acute, Abdominal Pain, Colic, Colonic Pseudo-Obstruction, Constipation, Dehydration, Fluid Therapy, Gastroenterology, Ileus, Intestinal Obstruction, Intestinal [ebm-guidelines.com]

  She was experiencing increasing abdominal pain and bloody diarrhea. Symptoms – Moderate abdominal pain, localized to the right lower quadrant, low-grade fever (37.9C). Physical – The abdomen was mildly distended. [undergradimaging.pressbooks.com]

  An 81-year-old man with a history of hypertension was admitted for complaints of abdominal pain, bloating, and anorexia persisting for 4 mo. An abdominal computed tomography revealed intestinal ileus. [ncbi.nlm.nih.gov]

• Abdominal Distension

  distension; and the absence of flatus. [ncbi.nlm.nih.gov]

  Symptoms and signs of ileus Primary features of postoperative or paralytic ileus include nausea and vomiting, inability to tolerate oral intake of food, abdominal distension, as well as the delayed passage of flatus and stool. [news-medical.net]

  This patient with spina bifida presented with abdominal distension. This radiograph shows dilatation of the entire colon, which measures almost 11 cm. There are no dilated small bowel loops. [svuhradiology.ie]

  Baby is uncomfortable, restless, and averse to feed due to abdominal discomfort and distension. [lecturio.com]

  This causes the air and food to get backed up in the digestive tract, which causes abdominal distension, or bloating, and abdominal pain. An ileus can happen in children and adults. [sclhealth.org]

• Hypotension

  gas, and intestinal contents can build up pressure and cause the bowel to collapse, collapsed bowel can build up pressure and lead to leakage of F&E into peritoneal cavity and ultimately lead to severe reduction in blood volume which can result in hypotension [slideshare.net]

  On examination, the patient can be severely dehydrated, which results in hypotension, tachycardia and the loss of skin turgor. The distended abdomen is often tympanic. [news-medical.net]

  On day five after initial presentation, the patient became bradycardic and hypotensive, progressed to asystole, and was pronounced dead. [karger.com]

  Sepsis related to gram-negative bacteria can present with hypotension, hypothermia, and bradycardia. Tachyphemia may suggest a pulmonary origin such as a pulmonary embolis ( Ruis-Tovar et al., 2010 ). [nursingcenter.com]

  […] output syndrome) or chronic hemodialysis, when the three of the four following criteria are completed: abdominal symptoms, including abdominal pain, vomiting occur and ileus develop; catecholamine use (cause spasm of splanchnic artery); presence of hypotension [journals.viamedica.pl]

• Tachycardia

  Approximately 2 weeks later, the patient was readmitted to the hospital for tachycardia and leukocytosis with concern for a possible bowel perforation. [nursingcenter.com]

  On examination, the patient can be severely dehydrated, which results in hypotension, tachycardia and the loss of skin turgor. The distended abdomen is often tympanic. [news-medical.net]

  A hypovolemic patient may be expected to present with mild tachycardia or hypotension, though severe abnormalities could indicate a different diagnosis. [medigoo.com]

• Uremia

  Paralytic ileus may also be caused by peritonitis; ischemia or surgical manipulation of the bowel; retroperitoneal hemorrhage; spinal fracture; systemic sepsis; shock; hypokalemia; uremia; pharmacologic agents (eg, vincristine, loperamide, and calcium [patientcareonline.com]

  […] viscus) studies laboratory studies are to be ordered given the clinical presentation to determine etiology/cause electrolyte panel hypokalemia and hypercalcemia may worsen ileus; hypomagnesemia can lead to hypokalemia creatinine and blood urea nitrogen uremia [step2.medbullets.com]

  […] abdominal penetrating injury, inflammatory bowel disease). 2) Renal colic accompanying kidney stones or urinary tract infection. 3) Biliopancreatic diseases. 4) Metabolic disturbances (ketoacidosis in patients with diabetes mellitus or ethanol poisoning, uremia [empendium.com]

  […] peristalsis of the gastrointestinal tract in the absence of mechanical obstruction Etiology Intra-abdominal surgery (postoperative ileus) Abdominal trauma; (e.g., due to retroperitoneal hemorrhage) Endocrine abnormalities (e.g., hypothyroidism, porphyria, uremia [amboss.com]

  […] eg, anesthesia, opioids, psychotropics, anticholinergics, antacids, warfarin, amitriptyline, chlorpromazine) Endocrine disorders (eg, diabetes, adrenal insufficiency, hypothyroidism) Metabolic (eg, low potassium, magnesium, or sodium levels; anemia ; uremia [emedicine.medscape.com]

• Plain abdominal X-ray is an important investigation in ileus. It is done with the patient in the supine and erect positions and it will show copious gaseous dilatation of the small intestine and colon. 
• Enteroclysis is an X-ray of the small intestine using liquid contrast and studying how it moves. It is expected that the contrast medium should reach the cecum within 4 hours if the patient has paralytic ileus. If it remains motionless for more than 4 hours, then mechanical obstruction is more likely.
• Ultrasound scans are also useful in the evaluation of this condition and can accurately exclude the condition in approximately 89% of patients.
• CT scan may be employed if a high index of suspicion remains despite normal X-ray findings.
• Laboratory investigations that could be done include complete blood count, erythrocyte sedimentation rate, and blood culture to evaluate for infections. Serum electrolytes, urea and creatinine as well as blood glucose studies should be done to check for metabolic imbalance [7]. 

• Bowel Distention

  Paralytic ileus typically presents with abdominal distention and minimal pain, which intensifies with increasing distention. Bowel sounds are generally minimal or absent. [patientcareonline.com]

  Fluid sequestration in the small bowel increases bowel distention, a vicious circle ensues. [mysurgery.de]

  Definition Ileus is a type of bowel obstruction. It happens when wavelike contractions stop. This is called peristalsis. Peristalsis pushes material along the digestive pathway. Small Bowel Distention Copyright © Nucleus Medical Media, Inc. [winchesterhospital.org]

  Small Bowel Distention Causes An Ileus may be caused any of the following conditions: Abdominal surgery. Joint or spine surgery. Injury or trauma. Infections, such as: Abdominal infections: peritonitis, appendicitis, diverticulitis and Pneumonia. [stomawise.co.uk]

  These include, the fixed anatomy, gas distribution, degree of bowel distention, air fluid levels, and arrangement of the bowel loops. [hawaii.edu]

• The management of this condition depends greatly on the surgical procedure performed and also on the nature of the disease. Management of this condition aims to resolve the underlying medical conditions, correct electrolyte imbalance and regulate acid base irregularities. 
• Most cases that occur postoperatively will resolve with supportive therapy and watchful waiting. Patients should be placed on intravenous infusion and a fluid chart kept to monitor intake and output. In patient who are vomiting and who have abdominal distension, a nasogastric tube may be passed to help relieve symptoms. Drugs that cause ileus like opiates should be discontinued. Non-steroidal anti-inflammatory drugs (NSAIDs) should be used instead for pain management and it also has the additional advantage of reducing local inflammation. The drugs of choice is Celobix (COX 2 selective agent) as it eliminates the unwanted effect of platelet dysfunction seen with non-selective NSAIDs [8].
• Oral feeding should be delayed until the ileus resolves clinically. It has been advocated that chewing gum helps to promote recovery from ileus postoperatively [9]. 
• Surgery may be required if the is a complication like perforation but this is rarely the case.

The prognosis is generally good as most cases of postoperative ileus resolve within 72 hours. Very rarely is there complication. The risk of a future occurrence is however increased in a patient who has had ileus [5].

The cause of ileus is still uncertain but there have been strongly linked associated risk factors. The main identified risk factor is major gastrointestinal surgery and the postoperative state is the most popular setting for development of ileus and it is an expected complication. Other contributing factors are electrolyte imbalance, hypothyrpidism, metabolic acidosis e.g. diabetic ketoacidosis, drugs like antimuscarinics and opiates, spinal cord injury above the fifth thoracic vertebrae, chest infections, cardiopulmonary failure like myocardial infarction, sepsis, intraabdominal inflammation and peritonitis, as well as biliary and renal colic [2].

Approximately 50% of people who undergo major abdominal surgery will develop ileus postoperatively. It is seen in all age groups although it is becoming more common in the elderly, probably due to increased surgical procedures now being performed in this age group. It has no sex preferences and affects individuals of all races [3].

The exact pathway by which ileus occurs is still unclear. It has been hypothesised that it might be mediated through activation of inhibitory spinal reflex arcs. 3 separate reflexes are involved, the long, short and ultrashort reflex. The long reflexes which involve the spinal cord is the most significant. Nerve cutting techniques have been seen to either diminish or prevent the development of ileus.
Usually, the response to surgical stress leads to systemic generation of endocrine and inflammatory mediators that then promote the development of ileus. Abdominal surgeries causes increased number of monocytes, macrophages, dendritic cells, natural killer cells, T cells and mast cells. Macrophages and mast cells are the key players in the inflammatory cascade. Other mediators are nitric oxide, calcitonin gene-related peptide, substance P and vasoactive inhibitory peptide and these serve as inhibitory neurotransmitters in the nervous system of the bowel [4].

Not much is available in terms of prevention of this condition. It occurs as a result of surgery, medical conditions and injuries which makes it difficult to control [10].

Ileus initially referred to any form of intestinal obstruction including mechanical obstruction. It is however now limited to intestinal obstruction resulting from failure of peristalsis. It is a very common post-operative complication in abdominal surgery [1].

• Definition: Ileus is a type of obstruction of the intestine that is not due to a mechanical cause i.e. blockage. Is arises when the normal movement of food and faecal matter in the intestines stop. It can be seen in any age group.
• Cause: More than half of the cases usually occur after surgery. Other causes may include, infections of the abdomen or chest, heart attack, certain types of drugs, injury to the intestine, imbalance of electrolytes like potassium and a previous history of ileus.
• Symptoms: The most common symptom is pain, this is initially vague but may become like cramps. There is also abdominal swelling, hiccups, nausea and vomiting and most patients will not be able to pass gas or stool.
• Diagnosis: Plain X-rays are usually enough to make a diagnosis of ileus. But ultrasound, CT scan and contrast X-rays also have their application. Blood tests will also be done to check for infections as well as underlying factors like electrolyte imbalance or diabetes.
• Treatment: The treatment is most often conservative as most postoperative cases resolve within 72 hours. Fluid is given intravenously, feeding is withheld and if necessary, stomach and small bowel is drained with a nasogastric tube. When drug treatment is instituted, it is to correct the underlying conditions.

1. Holte K, Kehlet H. Postoperative ileus: a preventable event. Br J Surg 2000; 87:1480.
2. Lyer S, Saunders WB, Stemkowski S. Economic burden of postoperative ileus associated with colectomy in the United States. J Manage Care Pharm. 2009;15:485
3. Ramirez JA, McIntosh AG, Strehlow R, et al. Definition, incidence, risk factors, and prevention of paralytic ileus following radical cystectomy: a systematic review. Eur Urol 2013; 64:588.
4. Livingston EH, Passaro EP Jr. Postoperative ileus. Dig Dis Sci 1990; 35:121.
5. Boeckxstaens GE, de Jonge WJ. Neuroimmune mechanisms in postoperative ileus. Gut 2009; 58:1300.
6. Behm B, Stollman N. Postoperative ileus: etiologies and interventions. Clin Gastroenterol Hepatol. Mar 2003;1(2):71-80
7. Barquist E, Bonaz B, Martinez V, et al. Neuronal pathways involved in abdominal surgery-induced gastric ileus in rats. Am J Physiol 1996; 270:R888.
8. Luckey A, Livingston E, Taché Y. Mechanisms and treatment of postoperative ileus. Arch Surg 2003; 138:206.
9. Asao T, Kuwano H, Nakamura J, et al. Gum chewing enhances early recovery from postoperative ileus after laparoscopic colectomy. J Am Coll Surg 2002; 195:30.
10. Yeh YC, Klinger EV, Reddy P. Pharmacologic options to prevent postoperative ileus. Ann Pharmacother. Sep 2009;43(9):1474-85