Your body produces enzymes to help you break down the food you eat and properly absorb their nutrients. Some foods naturally contain enzymes to facilitate their digestion, such as bromealin in pineapple and papain in papaya. Although watermelon and avocado may also contain small amounts of enzymes, they are not likely to cause abdominal pain. However, the types of sugars found in these foods can be associated with gastrointestinal discomfort.
Watermelon contains four different substances that can be associated with abdominal pain, bloating, constipation, diarrhea and flatulence in sensitive people. If you experience abdominal pain after eating watermelon, it could be due to either the fructose, fructans, mannitol or salicylates it contains. All of these compounds are naturally found in many foods, but they can trigger gastrointestinal problems in people who are intolerant or sensitive to some of these sugars or natural food chemicals.
Avocado is also rich in potentially problematic substances, including sorbitol, salicylates and amines. All of these compounds are natural and well-tolerated by most people. But you may be sensitive to these substances and thus experience abdominal pain accompanied by other gastrointestinal symptoms, such as changes in your bowel movements, excessive flatulence and abdominal bloating.
The abdominal pain you might experience after eating watermelon and avocado is not due to enzymes but rather to the poor absorption of the fructose, fructans, mannitol or sorbitol they contain. All of these compounds can be classified as short-chain fermentable carbohydrates. If you do not absorb them well, the bacteria present in your intestines will ferment these sugars, leading to many gastrointestinal problems, including abdominal pain. The salicylates and amines also present in both watermelon and avocados are natural chemicals. If you are intolerant to these compounds, you can suffer from abdominal pain when eating watermelon, avocado or other foods containing these chemicals.
Consult Your Health Professional
Whenever you experience abdominal pain that lasts for more than a few days, consult your doctor just to ensure you are not experiencing serious health problems. Your doctor can also refer you for some tests to determine whether short-chain fermentable carbohydrates or food chemicals are the cause of your abdominal pain. A registered dietitian specializing in gastrointestinal health might help you identify the foods that may trigger your symptoms and establish a diet plan that will help you get rid of your abdominal pain.