Which of the following is NOT a symptom of SIBO?

Small intestinal bacterial overgrowth (SIBO) typically presents with a variety of gastrointestinal symptoms due to the excessive growth of bacteria in the small intestine. Common symptoms associated with SIBO include abdominal pain, bloating, and watery diarrhea, which occurs because the increased bacteria can cause malabsorption and lead to diarrhea as a result of the fermentation of undigested carbohydrates.

Constipation, however, is less commonly associated with SIBO. While it can occur, the more frequent symptom associated with SIBO is diarrhea due to the overgrowth disrupting normal intestinal function. Therefore, when considering SIBO symptoms, constipation does not fit as typical or characteristic compared to the more prevalent symptoms of abdominal pain, bloating, and watery diarrhea. This context supports the reasoning for identifying constipation as not being a hallmark symptom of SIBO.