What is bowel obstruction caused by?
Bowel obstruction usually occurs when the lumen of the intestine is either obstructed by fecal matter or other debris/foreign bodies, or is compressed by external forces such as tumors or adhesions. These are called a “mechanical” cause of the obstruction. When there is a condition in which the bowel does not work correctly, but there is no structural problem causing it, it is called “ileus.” We are going to talk about mechanical bowel obstruction in this coding tip.
Mechanical bowel obstruction can be caused by a number of conditions. Some of the most common causes are:
- Adhesions or scar tissue that forms after surgery
- Foreign bodies (objects that are swallowed and block the intestines)
- Gallstones (rare)
- Impacted stool
- Intussusception (telescoping of one segment of bowel into another)
- Tumors blocking the intestines
- Volvulus (twisted intestine)
Symptoms may include:
- Abdominal swelling (distention)
- Abdominal fullness, gas
- Abdominal pain and cramping
- Breath odor
- Inability to pass gas
Exams and Tests
During a physical exam, the health care provider may find bloating, tenderness, or hernias in the abdomen.
Tests that show obstruction include:
- Abdominal CT scan
- Abdominal x-ray
- Barium enema
- Upper GI and small bowel series
Treatment involves placing a tube through the nose into the stomach or intestine. This is to help relieve abdominal swelling (distention) and vomiting. Volvulus of the large bowel may be treated by passing a tube into the rectum.
Surgery may be needed to relieve the obstruction if the tube does not relieve the symptoms. It may also be needed if there are signs of tissue death.
How is bowel obstruction coded in ICD-10-CM?
Bowel obstruction can be due to many different causes as was stated above. The ICD-10-CM index can be a little tricky when coding intestinal obstruction. Some encoders actually put in a warning entry such as the entries in red below that reflect tabular excludes1 notes and Coding Clinic advice. See the index entry below:
ICD-10-CM Index entry for obstruction, intestine: (*Red is added by encoder company)
*peritoneal carcinomatosis (Coding Clinic for ICD-10 2Q 2017) C78.6
*specified condition (ICD-10-CM Code Book) – code to condition
adhesions (intestinal) (peritoneal) K56.50
by gallstone K56.3
congenital (small) Q41.9
specified part NEC Q42.8
Hirschsprung’s disease or megacolon Q43.1
inspissated milk P76.2
meconium (plug) P76.0
in mucoviscidosis E84.11
specified NEC P76.8
specified NEC K56.699
Code assignment starts with the index along with medical record documentation as to the cause of the intestinal obstruction. There are also entries for “partial” or “complete” intestinal obstruction, so the coder will need to look for that documentation. Note that it does not make any difference if it is the small or large intestine that is obstructed in code assignment.
If the physician documents a large intestine obstruction for example, and does not find a specific cause, then the unspecified code, K56.609, Unspecified intestinal obstruction, unspecified as to partial versus complete obstruction is assigned. There is no condition associated with it so it is unspecified.
Where we find coders making the biggest mistake is assigning a code for bowel obstruction when the condition causing it is also linked and documented in the record. When coders do this, the intestinal obstruction code is a CC for the DRG in that case which affects reimbursement if it is the only CC on the case. For example, take large intestine obstruction due to large metastatic tumor to the peritoneum, original ovarian tumor having been removed previously. In this case, the code for intestine obstruction would NOT be coded. Assign only code C78.6, Secondary malignant neoplasm of retroperitoneum and peritoneum, as instructed by the Excludes 1 notes found under codes K56.60, Unspecified intestinal obstruction, and K56.69, Other intestinal obstruction, which state: “intestinal obstruction due to specified condition-code to condition.” An additional code can be added for the history of ovarian carcinoma. Coding Clinic, Second Quarter 2017: Page 12 instructs to use only the C78.6 code it the above example.
Here is the tabular for specified condition causing intestinal obstruction that coders must follow:
K56.69 Other intestinal obstruction
Obstructive ileus NOS
Occlusion of colon or intestine NOS
Stenosis of colon or intestine NOS
Stricture of colon or intestine NOS
Excludes1: intestinal obstruction due to specified condition-code to condition
K56.690 Other partial intestinal
K56.691 Other complete intestinal obstruction
K56.699 Other intestinal obstruction unspecified as to partial versus complete obstruction
Other intestinal obstruction, NEC
In addition, coders may see Excludes1 note at K56 that excludes intestinal obstruction with these conditions.
K56 Paralytic ileus and intestinal obstruction without hernia
Excludes1: congenital stricture or stenosis of intestine (Q41-Q42)
cystic fibrosis with meconium ileus (E84.11)
ischemic stricture of intestine (K55.1)
meconium ileus NOS (P76.0)
neonatal intestinal obstructions classifiable to P76.-
obstruction of duodenum (K31.5)
postprocedural intestinal obstruction (K91.3-)
Excludes2: stenosis of anus or rectum (K62.4)
In addition, certain conditions will include a “with” notation and code within the index. See Adhesions entry below from the index:
Adhesions, adhesive (postinfective) K66.0
with intestinal obstruction K56.50
So given the above, if a patient has intestinal obstruction due to adhesions, only code K56.50, intestinal adhesions [bands], unspecified as to partial versus complete obstruction would be assigned, not two codes.
Lastly, if intestinal obstruction is a complication of surgery, code K91.3-, may be warranted. Coders must validate that this is truly intestinal obstruction as a complication of surgery, and not just occurring after surgery due to another cause. The term “postoperative’ can be misleading. A query may be necessary.
- Coders must be aware of the index entries for intestinal obstruction and follow the index
- For conditions in the index, look for “with obstruction” underneath the main entry or subterm entries
- If intestinal obstruction is due to a documented condition not listed in the index under obstruction, intestinal, the documented condition is coded and NOT the intestinal obstruction code
- Always follow the Excludes1 notes at these codes in the tabular, and at time these are located at the three digit section code or chapter beginning rather than only individual codes
- Check the documentation for “partial” or “complete” obstruction and for the documented cause of intestine obstruction
- Check the documentation for “postoperative” bowel obstruction and documentation that it is a complication of surgery. If in doubt query the physician.
The information contained in this post is valid at the time of posting. Viewers are encouraged to research subsequent official guidance in the areas associated with the topic as they can change rapidly.