Codes K58.1, Irritable bowel syndrome with constipation; K58.2, Mixed irritable bowel syndrome; and K58.8, Other irritable bowel syndrome, have been created to distinguish types of irritable bowel syndrome.
Irritable bowel syndrome (IBS) is characterized by abdominal pain or discomfort, bloating and changes in bowel movement. There are four types of IBS that are based on the predominant alteration in stool consistency: IBS-C, with constipation, IBS-D, with diarrhea, IBS-M, mixed IBS (both constipation and diarrhea) and IBS-U, unsubtyped IBS (diarrhea and constipation less than 25% of the time).
IBS is a functional gastrointestinal disorder that affects 10% to 15% of the adult population. A thorough history and examination are important in obtaining the diagnosis. Colonoscopy and imaging are necessary to rule out other conditions.
The type of IBS and symptoms determines the treatment. Medication may reduce constipation and diarrhea. Medications that affect serotonin levels or serotonin receptors have been noted to improve symptoms by working on the nerves of the bowel.