Do Bananas Make You Poop Or Cause Constipation? Experts Weigh In

Many people can agree that bananas are a versatile and nutritious snack—whether blended into a smoothie, mashed in banana bread, or sliced on top of toast with peanut butter. What's still up for debate, however, is whether or not bananas help with constipation or cause it. 

"Both pectin and resistant starch function similarly to soluble fiber," Carrasco says, "and also have a prebiotic effect, feeding your good bacteria." 

So while green bananas are good for overall gut health, the resistant starches will be harder to digest. "Thus, they can cause or aggravate preexisting constipation," one study says1. In fact, family physician Bindiya Gandhi, M.D., says they have been shown to help manage diarrhea2.

"Yellow bananas lose their starch content as they start to ripen," Carrasco says. The starch doesn't just disappear, though. It converts into simple sugars, increasing both the glycemic index and the sweetness of the banana. As the resistant starches break down, the banana becomes easier to digest. 

Yellow bananas are also relatively high in soluble and insoluble fibers (about 3 grams per medium-size banana), which helps promote regularity3. 

Brown bananas, like yellow, will continue to lose resistant starch over time. Because they're higher in both sugars and carbohydrates, Gandhi says they can have inflammatory effects on some people. 

For those who aren't affected, though, brown bananas can be beneficial for digestion because of their low resistant starches. They're also the highest in antioxidants4, according to Carrasco.