In cancer support communities, sharing seasonal vegetables and fruit is common, and pumpkin (also called squash) often arrives with the belief that it "drains swelling after surgery." Pumpkin does have real nutritional strengths, but it helps to separate what it can do from what it cannot, rather than treating it as a medicine for edema (swelling).
Pumpkin is rich in beta-carotene, which the body converts to vitamin A, and it also supplies fiber and potassium. It is naturally low in fat and calories, which makes it easy to enjoy during recovery as porridge, soup, or a simple steamed dish. After gastrointestinal surgery in particular, when meals are being reintroduced slowly, softly cooked pumpkin can be gentle on the stomach and easy to swallow.
The idea that pumpkin "removes swelling" comes from the mild diuretic effect of potassium, which helps balance sodium in the body and may ease temporary puffiness from a salty meal. However, the arm or leg swelling that can follow cancer surgery (lymphedema), or the whole-body swelling caused by heart, kidney, or liver problems or low albumin, will not resolve simply by eating pumpkin. These types of edema need their underlying cause identified and managed, and relying on "pumpkin water" alone may delay the care that is actually needed.
A few cautions matter. Because pumpkin is high in potassium, anyone with reduced kidney function or who needs to watch their potassium levels may need to limit the amount. Sweeter varieties are also higher in carbohydrate and sugar, so people managing blood sugar should avoid eating large portions at once and go easy on added sugar during cooking.
In short, pumpkin is a comforting, easy-to-digest food to enjoy during recovery, but it is not a treatment for edema. If swelling suddenly worsens, appears in only one arm or leg, or comes with shortness of breath or rapid weight gain, please speak with your care team rather than trying to fix it with food. This article is general information and does not replace your own medical care, so please discuss decisions about your situation with your treating clinicians.