Which condition affects the large intestine and presents with abdominal cramps, bloating, and changes in bowel habits, including diarrhea or constipation, with no known single cause?

• A. Hemorrhoids
• B. Hepatitis
• C. IBS (irritable bowel syndrome)
• D. Peptic ulcer

Answer: (C)

The focus is identifying a functional bowel disorder of the large intestine that causes recurrent abdominal cramps, bloating, and changes in bowel habits (diarrhea, constipation, or both) without a single identifiable cause. This description fits irritable bowel syndrome. IBS is a functional GI disorder where the bowel looks normal on tests, but symptoms arise from how the gut and brain interact and move, not from a clear structural disease. Its causes are multifactorial—altered intestinal motility, increased gut sensitivity, changes in the gut-brain axis, microbiome differences, and psychosocial factors like stress can all play a role. Because there isn’t a specific underlying disease to point to, IBS is characterized by a cluster of symptoms rather than a single identifiable pathology.

Hemorrhoids mainly cause rectal bleeding, itching, and discomfort near the anal canal, not the cramping and bloating typical of IBS. Hepatitis involves the liver and presents with symptoms like fatigue, jaundice, and abnormal liver tests. Peptic ulcers affect the stomach or first part of the small intestine and cause upper abdominal pain often related to meals, not primarily chronic changes in bowel habits.