My father was recently diagnosed with rectal cancer.  He had a 
colectomy on January 13.  Since then, he has been hospitalized four 
times with a suspected "obstruction".  Problem is, they can't seem to 
find the obstruction.  They have given him an extensive battery of 
tests- and seem to have no conclusive answers as to why he can't seem 
to hold food down (they have to drain the stomach every time he goes 
in).  He is very frustrated (obviously) and I'm really trying to find 
out what might be going on.  Here are my quesitons.  First, is it 
normal to be hospitalized so many times for an obstruction that can't 
be found?  Second, is there ANY other condition that would prevent him 
from properly digesting food?  He is a patient at Emory University 
Hospital in Atlanta. 
Thank You! 
Dottie Sutherland, MBA, PhD 
Tucson, AZ

Hello - thanks for requesting me to answer your question.

Although I am an internal medicine physician, please see your primary
care physician for specific questions regarding any individual cases –
please do not use Google Answers as a substitute for medical advice. 
I will be happy to answer factual medical questions.

You are asking about causes of "obstruction" that cannot be found.  By
an "extensive battery of tests", I am going to assume he already had
upper and lower endoscopies and CT scans which would exclude obvious
causes.

"First, is it normal to be hospitalized so many times for an
obstruction that can't be found?  Second, is there ANY other condition
that would prevent him from properly digesting food?"

Colonic obstruction is generally caused be 3 entities: i) Toxic
megacolon (eg, as a complication of inflammatory bowel disease or
Clostridium difficile infection); ii) Mechanical obstruction; iii)
colonic pseudo-obstruction.  The first two causes would be excluded by
a CT scan and endoscopies.  I will discuss the third cause - they are
divided into acute and chronic pseudo-obstruction.

Acute pseudoobstruction:

Acute colonic pseudo-obstruction (Ogilvie's syndrome) is a disorder
characterized by gross dilatation of the cecum and right hemicolon
(although occasionally extending to the rectum), in the absence of an
anatomic lesion that obstructs the flow of intestinal contents.

Diseases associated with Ogilvie's syndrome include trauma, pelvic,
abdominal, or cardiothoracic surgery, severe medical illness
(pneumonia, MI, CHF), neurologicl conditions or retroperitoneal
pathology (i.e. malignancy or hemorrhage).

Acute colonic pseudo-obstruction is more common in men and in patients
over the age of 60. Nausea, vomiting, abdominal pain, constipation,
and, paradoxically, diarrhea are the primary manifestations although
they occur with great variability. Abdominal distention is always
present and can cause labored breathing.

The diagnosis of acute colonic pseudo-obstruction can be made only
after excluding the presence of toxic megacolon or mechanical
obstruction. Patients with mechanical obstruction frequently complain
of crampy abdominal pain; however, lack of pain, especially in the
elderly or postoperative patient receiving narcotics, does not exclude
that diagnosis.

There are few controlled trials comparing treatments of acute colonic
pseudo-obstruction. Thus, recommendations are based largely upon
retrospective reviews and anecdotal experiences. Management includes
the following:

- Supportive care and removal of possible precipitants (eg, opiates,
anticholinergics)
- Pharmacologic agents or gentle enemas which might stimulate colonic
motility (i.e. neostigmine, erythromycin)
- Colonoscopic decompression
- Surgery

Chronic pseudo-obstruction:

Chronic intestinal pseudo-obstruction is a syndrome that suggests
mechanical bowel obstruction of the small or large bowel in the
absence of an anatomic lesion that obstructs the flow of intestinal
contents.

Several patients have been described with small cell lung cancers or
carcinoid tumors in association with a paraneoplastic gastrointestinal
motility disorder.

The clinical symptoms of chronic intestinal pseudo-obstruction are
similar to those that suggest upper gut stasis. One review of 42
patients found the main clinical manifestations were as follows (1):

- Nausea and vomiting — 83 percent
- Abdominal pain — 74 percent
- Distension — 57 percent
- Constipation — 36 percent
- Diarrhea — 29 percent
- Urinary symptoms — 17 percent

There are four important steps in the evaluation of patients with
suspected intestinal pseudo-obstruction:

- Radiographic testing
- Assessment of nutritional status
- Confirmation of dysmotility with a transit test 
- Performance of specialized tests such as manometry 

Other causes of gastrointestintal motility disorders:

Anatomical Region - disorder:
Esophagus - achalasia
Stomach - acute gastric dilatation, gastroparesis
Small bowel - pseudoobstruction, chronic intestinal dysmotility
Colon - megacolon/pseudoobstruction, slow transit constipation/colonic
inertia

You may want to discuss these conditions with your personal
gastroenterologist.

I stress that this answer is not intended as and does not substitute 
for medical advice - please see your personal physician for further 
evaluation of your individual case. 
      
Please use any answer clarification before rating this answer. I will
be happy to explain or expand on any issue you may have.    
          
Thanks,           
Kevin, M.D.    
  
Search strategy:   
No internet search engine was used in this answer.  All sources are  
from physician-written and peer-reviewed sources.  

Bibliography:
1) Stanghellini, V, Camilleri, M, Malagelada, JR. Chronic idiopathic
intestinal pseudo-obstruction: Clinical and intestinal manometric
findings. Gut 1987; 28:5.
2) Camilleri.  Acute colonic pseudoobstruction.  UptoDate, 2002.
3) Camilleri.  Chronic colonic pseudoobstruction.  UptoDate, 2002.

Links:
Medline Plus - Primary or idiopathic intestinal pseudo-obstruction
http://www.nlm.nih.gov/medlineplus/ency/article/000253.htm

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intermittant obstruction after surgery can be a difficult problem: if
it clears by the time the tests are done, it may be impossible to
confirm or identify. The diagnosis depends on the clinical situation,
and the xrays done immediatly when seen: plain films can help
distinguish if the abdominal gas pattern is consistent with
obstruction, or "lazy bowels" called ileus, or even stomach-emptying
problems. Any given obstruction, if it gets better on its own, may not
need surgery; but if it keeps happening, at some point the surgeons
must consider whether reoperation is appropriate, in the hope of
identifying the problem area and fixing it. The problem is that when
the symptoms keep clearing up, it may not be possible to be absolutely
certain that that is what the problem is; and reoperation may not
help. Certainly his original surgeons are involved with the current
decision making. Sometimes after major surgery, there are rare but
sometimes long periods where the gut or stomach or both just don't
recover typcially; somtimes other forms of nutrition become necessary
while waiting: intravenous (which can be done at home, nowadays) or
through a specially inserted tube into the intestine, using elemental
nutrients more easy to absorb.