PHYSICAL DIAGNOSIS OF SMALL BOWEL OBSTRUCTION

A middle aged man presented with worsening bloating, cramping abdominal pain, nausea, and vomiting. He had been in the ED the day before for similar symptoms, his x-rays were normal, and he had been diagnosed with gastroenteritis. With vomiting and cramping pain, you wonder about a bowel obstruction. Can physical diagnosis help?

LIMITATIONS OF RADIOGRAPHS

This is a very important topic because plain films have a sensitivity for small bowel obstruction approximately 50% and even noncontrast CT scan has limitations in sensitivity (Ros J Am Coll Radiol 2006).

DISTENSION IS HUGE!

The first thing is to recognize that intestinal obstruction is a heterogenous event, and presents differently according to the level of obstruction, whether proximal or distal. In general the more proximal obstructions present with dominant vomiting, and the distal obstructions present with prominent distension. This is huge (literally). When you see distension, pursue this finding, as it has high discriminatory value.(Eskelinen 1994)

SCARS OUTSIDE PREDICT SCARS INSIDE

The majority of patients (85%) with bowel obstruction have a history of previous abdominal surgery.(Eskelinen Scand J Gastroenterol 1994) In the poor historian, an abdominal scar is a useful proxy.

BOWEL SOUNDS

Diminished bowel sounds indicate ileus and increased bowel sounds indicate bowel obstruction, though there is overlap and these are neither sensitive nor specific.(Gu Dig Surg 2010) Listen for an increase in loudness, faster cycle times, and a higher pitch of sound. SBO can make everything higher: volume, frequency, pitch. If the radiologist says it is SBO vs ileus then the presence of bowel sounds is helpful in arguing against ileus. Gastroenteritis will cause increased bowel sounds.

OTHER FINDINGS

A history of constipation is present in only 37% but is 90% specific. Relief with vomiting is not common (19% sensitive) but very specific for bowel obstruction (93%) .

Take home points

-Note the history of abdominal surgeries or look for a scar

-Distension is huge! (sensitive and specific)

-Auscultation may have some value in ileus vs gastroenteritis vs SBO

DYSPHAGIA

A patient presents with difficulty feeding for the past month.  Specifically, she states that she is “unable” to swallow.  How do we perform the bedside examination so as to take this presentation to the highest degree of resolution?

 

Swallowing can be divided into 2 processes: oropharyngeal and esophageal.

 

The oropharyngeal process moves the food bolus from the back of the tongue to the pharynx, where the pharynx squeezes it into the upper esophagus.  This event involves the soft palate closing of the nasopharynx, the epiglottis closing of the tracheal entrance, and the upper esophageal sphincter transiently relaxing to accommodate the food bolus.  This is a complex neurological event, and oropharyngeal dysphagia is usually caused by a neurological disease.  Telltale signs include nasal and tracheal aspiration, as well as inability to propel food out of the pharynx.

 

The esophageal process moves food from the upper esophageal sphincter (cricopharyngeus) to the lower esophageal sphincter.  Disruption can be anatomic (obstruction) or physiologic (motility). It presents with the feeling that food gets stuck in the esophagus. Patients feel these symptoms in the chest.

 

Dysphagia to solids only (such as chewy meats) signifies an anatomic obstruction. Gastroenterologists use marshmallows to bring this out, and call it a “viscous swallow.” Typical causes of anatomic obstruction include stricture, ring, or cancer.

 

Dysphagia to liquids and solids signifies a physiologic motility disorder. These can be localized to the lower esophageal sphincter, such as achalasia, or can be diffuse, such as diffuse esophageal spasm. Motility orders can also be secondary to inflammation, such as in gastroesophageal reflux disease.

 

By clarifying which part of the swallow process is disordered as well as noting whether liquids are affected helps considerably narrow the differential diagnosis of dysphagia.

 

Summary:

-Inability to swallow or aspiration indicates oropharyngeal dysphagia, and is usually neurologic.

-Dysphagia to solids indicates obstruction.

-Dysphagia to liquids and solids indicates a motility disorder.