Do having endoscopy or colonoscopy and having anal or vaginal ultrasonography invalidate the fast?
During endoscopy performed to monitor the stomach or resect a piece from the stomach with the aim of diagnosing the illness of the stomach, a medical device is inserted through mouth and removed after the process. During colonoscopy performed to monitor the large intestines (colon) or resect a piece with the aim of diagnosing the illness of the intestines, a medical device is inserted through anus and removed after the process. During colonoscopy, almost always, and endoscopy, usually, water is given through the device to cleanse the parts to be monitored.
Although endoscopy, colonoscopy, and anal and vaginal ultrasonography are not considered as eating and drinking, fasting is invalidated because mostly water is given through the device. However, if a nutritional substance such as water, fat, etc. does not enter into the digestive system by use of those devices in such processes, endoscopy, colonoscopy or anal and vaginal ultrasonography do not invalidate fasting (Decision by HBRA dated 22. 09.2005; see. Kasani, Bada’i, II, 98; Ibn Abidin, Radd al-Muhtar, III, 367, 369, 376)
Source: Presidency Of Religious Affairs The Turkey, High Board of Religious Affairs FATWAS