11.12 Irritable Bowel Syndrome
Irritable bowel syndrome (IBS) is a chronic gastrointestinal disorder in which there is abdominal discomfort, along with a change in bowel patterns. There are three different subclasses of IBS: IBS-C, IBS-D, and IBS-M. In IBS-C, constipation is the predominant stool pattern. In IBS-D, diarrhea is the predominant stool pattern. With IBD-M, there is a mix of bowel movement types, alternating between diarrhea and constipation.
IBS is most common in women younger than 50 years old. Additionally, clients with anxiety, depression, or increased stress are more likely to experience IBS. Family history/genetics is a risk factor, and IBS is most common in clients from South America and least common in clients from Southeast Asia. Certain foods can also trigger IBS symptoms, such as dairy products; gas-producing foods such as cabbage and beans; carbonated beverages; and citrus fruits.
Pathophysiology
IBS is a functional disorder, meaning there are symptoms present but there is no correlating gastrointestinal disease. The cause of IBS is unknown, but there are many theories regarding the development of this disorder such as the following[1],[2]:
- Alterations in intestinal muscle contractions, with increased muscle contractions causing diarrhea and decreased or weak contractions causing constipation.
- Inappropriate nervous system signaling in the GI tract.
- Alterations in the normal intestinal flora when compared to clients without IBS.
- Changes in the immune response of the gastrointestinal tract.
- Environmental factors such as significant stress early in life, antibiotic use, infections such as gastroenteritis, and the inability to tolerate certain foods.
Assessment
Physical Exam
Common signs and symptoms of IBS include the following[3]:
- Abdominal pain
- A change in bowel habits such as diarrhea, constipation, or alternating diarrhea and constipation
- Abdominal distention or bloating
- Correlation of symptoms with intake of certain foods that are relieved by bowel movements
There is no specific diagnostic test for IBS, but it is typically diagnosed by a health care provider using Rome IV criteria. Criteria include recurrent abdominal pain at least one day per week associated with two or more of the following symptoms over a three-month time span[4]:
- Abdominal pain that improves after having a bowel movement
- Alterations in stool frequency
- Alterations in the appearance of stool
Common Laboratory and Diagnostic Tests
There are no diagnostic tests for IBS. However, if other alarming symptoms are present, such as blood in stool or unexpected weight loss, blood tests such as a complete blood count or metabolic panel may be done to rule out other causative factors. If diarrhea is an associated symptom, stool tests may be ordered to rule out an infectious cause. A colonoscopy may also be ordered, especially if there is a family history of gastrointestinal cancer or IBD.[5]
Nursing Diagnosis
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