Hello I appreciate yourconcern for your friend Looking at your description with habit of less water intake this could be UTI, ureteric colic or renal stone Another possibility is colitis due to long standing constipation In my opinion he should consult a doctor for examination and a battery of tests like blood and urine test with an ultrasound to confirm the diagnosis Meanwhile ask him to have plenty of fluids and avoid constipation by taking laxative or stool softening agent like liquid paraffin Maintain good hygiene and follow aseptic precautions by washing hands regularly If you can provide me more information like his age and complete medical history I will be able to guide him better Thanks and regards