Internal Medicine Coding Alert

Hint: You use the same diagnosis code for spastic colon.

When your clinician diagnoses irritable bowel syndrome (IBS), you will have to look for symptoms of diarrhea as this will affect code choice in ICD-10. 

ICD-9: When your internal medicine physician arrives at a diagnosis of irritable bowel syndrome, you report it with 564.1 (Irritable bowel syndrome). You use the same ICD-9 code if your clinician’s diagnosis is either spastic colon or irritable colon.

You cannot use 564.1 if your clinician diagnoses functional disorders of the stomach. You report it with a code from the range, 536.0-536.9. You also cannot use 564.1 for other functional digestive disorders not classified elsewhere that are specified as psychogenic (e.g. psychogenic diarrhea). You report those with the ICD-9 code, 306.4 (Physiological malfunction arising from mental factors; Gastrointestinal).

ICD-10: When you are reporting a diagnosis of IBS with ICD-10 codes, you will have to check further into the patient’s chart, as you have more options than a simple crossover one-to-one code for this condition. You begin your choice with the ICD-10 code, K58.- (Irritable bowel syndrome). However, K58 further expands into two different codes depending on the presence or absence of diarrhea:

• K58.0 --- Irritable bowel syndrome with diarrhea
• K58.9 --- Irritable bowel syndrome without diarrhea. 
  This code is also used if presence or absence of diarrhea is not specified (i.e., for irritable bowel syndrome not otherwise specified).

As in ICD-9, you will use the same diagnosis codes (depending on presence or absence of diarrhea) when your clinician diagnoses the patient with spastic colon or irritable colon.

Gather More Information From These Basics

Documentation spotlight: Your physician will arrive at a final diagnosis of irritable bowel syndrome based on findings of history, examination, imaging studies, and laboratory findings.

Some of the common findings that you are more likely to note in a patient with IBS will include abdominal cramping and discomfort; flatulence; bloating and abdominal distension; episodes of diarrhea and constipation; and changes to bowel habits.

Tests: Some of the tests that your clinician is most likely to order when he suspects the patient to be suffering from IBS will include blood tests and stool tests to rule out the possibility of other conditions with similar symptoms. He might also ask for imaging studies such as CT scan or an x-ray of the small intestine.

Example: An internist reviews a 52-year-old male new patient with complaints of pain in the abdominal area and flatulence. He also complains of some degree of diarrhea, cramping, and distension. He says that he has been having these kinds of symptoms for some time now and they have been aggravating on and off. He also says that he has episodic events of diarrhea followed by many days of constipation. He says that he has been to many other doctors before, but there has been no permanent remedy to his problems.

Your clinician performs a thorough evaluation of the patient. He orders a complete blood count and stool tests to check for blood in the stools. He also asks for a CT scan of the abdominal area to rule out other problems.

Based on history, signs and symptoms, and negative findings from lab tests and imaging studies, your clinician arrives at a diagnosis of IBS.

What to report:  You report the evaluation of the patient with an E/M code such as 99203 (Office or other outpatient visit for the evaluation and management of a new patient…). You report the diagnosis of the patient with 564.1 if you are using ICD-9 codes or report K58.0 when using ICD-10. You use this code choice in ICD-10 as the patient was also suffering from diarrhea.