Gastroenterology Coding Alert

There are almost two dozen codes to choose from within the K57 (Diverticular disease of intestine) category, so it’s important to familiarize yourself with these conditions before settling on a code.

Keep reading if you’ve ever had trouble, or you simply need a refresher on coding these can-be-confusing conditions.

Know the Difference Between the 2 Conditions

Diverticulitis is essentially an acute manifestation of diverticulosis. In other words, “you cannot get diverticulitis unless you have diverticulosis,” explains Carol Pohlig, BSN, RN, CPC, ACS, senior coding and education specialist in the department of medicine at the Hospital of the University of Pennsylvania in Philadelphia.

Diverticulosis occurs when small, bulging pouches called diverticula develop in the digestive tract. This most commonly occurs in the sigmoid colon where the pressure is greatest. It is mostly seen in people 40 years of age or older.

Diverticulitis occurs when one or more of the pouches (diverticula) develop perforations that become infected or inflamed. Bleeding may sometimes occur due to the small, fragile blood vessels at the edge of the diverticula, which sometimes require emergency intervention.

Review the K57 Codes

You’ll find the codes you need to document both conditions in Chapter 11: Diseases of the Digestive System (K00-K95). The descriptors for all the diverticular disease codes are very similar. You’ll see that correct coding demands you know where the diverticula reside, whether there is perforation or abscess, and whether there is bleeding. For example:

• K57.00 (Diverticulitis of small intestine with perforation and abscess without bleeding)
• K57.01 (… with bleeding)
• K57.10 (Diverticulosis of small intestine without perforation or abscess without bleeding)
• K57.11 (… with bleeding)
• K57.12 (Diverticulitis of small intestine without perforation or abscess without bleeding)
• K57.13 (… with bleeding)

The codes for diverticular conditions affecting the large intestine follow the same general coding pattern, starting with K57.2- (Diverticulitis of large intestine with perforation and abscess …) and ending with K57.3- (Diverticulosis/itis of large intestine without perforation or abscess …). You’ll choose a similar code from K57.4- (Diverticulitis of both small and large intestine …) or K57.5- (Diverticulosis/itis of both small and large intestine …) if the condition affects both the large and small intestines. Note that diverticulitis of the small intestine is relatively rare, so most of these codes will reference the colon.

In the absence of location details, you should consult your gastroenterologist before turning to unspecified codes K57.8- (Diverticulitis of intestine, part unspecified, with perforation and abscess …) through K57.93 (… part unspecified, without perforation …). Unspecified codes are often necessary when a condition has been confirmed but imaging hasn’t been performed. Once your provider performs an endoscopy on the patient, however, the location information for the condition exists, even if your provider has not documented it. So, make sure to query the provider when this occurs.

Coding alert: Notice the Excludes1 notes under the K57 parent. If the physician documents congenital diverticulum of intestine, code Q43.8 (Other specified congenital malformations of intestine). If the diagnosis is Meckel’s diverticulum, code Q43.0 (Meckel’s diverticulum (displaced) (hypertrophic)). Additionally, make sure you pay attention to the Excludes2 note, which tells you to code K38.2 (Diverticulum of appendix) in addition to a diverticular condition warranting a K57- code should your provider document both conditions.

Avoid These Common Coding Errors

Error 1 – mistaking diverticulosis for diverticulitis: Because the difference between K57.11 and K57.13 is just “-osis” versus “-itis,” it wouldn’t be difficult to accidentally report the wrong condition simply because you were reading the descriptors too quickly.

Another factor that can present a challenge to correct coding is that most patients with diverticulosis are asymptomatic. “But if the patient becomes symptomatic, coders may erroneously think the patient has therefore progressed from stable diverticulosis to diverticulitis,” Pohlig explains.

Error 2 – coding potential or “rule-out” diagnoses: When patients with diverticulosis do present with symptoms, those symptoms often overlap with several other conditions. For example, irritable bowel syndrome (IBS), Crohn’s disease, and ulcerative colitis all present with similar symptoms. Diverticulitis can be confirmed by an elevated white blood cell count, which would indicate infection. Also, radiological tests or endoscopy can identify inflammation. However, you will still need your provider to provide a definitive diagnosis. “If ever it’s unclear which diagnosis to code based on the documentation, it’s necessary to query the provider,” says Laidy Martinez, CPC, CGIC, CASCC, profee coder at Children’s Health of Orange County in Orange County, California.

Error 3 – neglecting to code signs and symptoms: When a patient presents to the gastroenterologist with symptoms such as bloating, cramping, constipation, or stomach pain, the gastroenterologist might perform an endoscopy to get a closer look. But until the physician performs the procedure and has the results, a definitive diagnosis isn’t available. As ICD-10 official guideline I.B.4 states, “Codes that describe signs, as opposed to diagnoses are acceptable for reporting purposes when a related definitive diagnosis has not been established (confirmed) by the provider.” Without a confirmed diagnosis, the encounter needs to include signs and symptoms codes such as K59.00 (Constipation, unspecified), R14.0 (Abdominal distension (gaseous)), and R10.84 (generalized abdominal pain).

Coding alert: Diverticulosis can cause a condition called peritonitis if one of the diverticula pouches ruptures and spills intestinal waste into the patient’s abdominal cavity. This is why you see a Code also note appears under the K57- category instructing you to report K65.- (Peritonitis) if applicable.

Remember to Report Applicable SDoH

“More attention is being drawn to patients’ social determinants of health,” says Pohlig. Social determinants of health (SDoH) codes can act as supplemental support to prove medical necessity for services. They also help round out a patient record for the sake of future treatments or other providers. For example, diverticulosis can often be controlled with diet, which means codes such as Z91.110 (Patient’s noncompliance with dietary regimen due to financial hardship), Z91.118 (Patient’s noncompliance with dietary regimen for other reason), or Z91.119 (Patient’s noncompliance with dietary regimen due to unspecified reason) are important codes to report when applicable.

“Social determinants of health can play a huge role when coding these two conditions,” explains Martinez. “If a diverticulosis patient is noncompliant with a recommended dietary regimen, specifically a high fiber diet, it could lead to waste buildup and constipation which puts pressure on the diverticula, putting the patient at risk of more serious illness,” she says. Therefore, be sure to add these codes to your claim when your provider documents SDoH affecting the patient’s disease or care.