You can also learn a lot about your health in the bathroom. “Significant changes in bodily functions can indicate colon, prostate or bladder cancer, among other cancers,” the experts at The University of California San Francisco Health (UCSFH) write. Read on to find out what symptoms to watch for—and when it’s time to head to the doctor for a checkup. READ THIS NEXT: If You Notice This on Your Skin, Get Checked for Pancreatic Cancer, Doctors Say. Some of the reasons for having to pee frequently are very obvious, like drinking a lot of water. However, running to the bathroom often can also signal a serious condition.ae0fcc31ae342fd3a1346ebb1f342fcb “Frequent urination can be a sign of bladder cancer, because the tumor can block the flow of urine out of the bladder or the cancer cells themselves can make the bladder wall thicker and less elastic and unable to hold as much urine as a normal bladder can,” cautions Alice Williams, MD, an emergency medicine physician. “As a result, patients often feel the need to urinate even when their bladder isn’t full.” According to the American Cancer Society (ACS), frequent urination, particularly at night, can signal prostate cancer. But “a slow or weak urinary stream” is another change that might be a sign of prostate cancer, says the site. Trouble peeing is “much more often caused by benign prostatic hyperplasia (BPH), a non-cancerous growth of the prostate,” advises the ACS. “Still, it’s important to tell your health care provider if you have any of these symptoms so that the cause can be found and treated, if needed.” Constipation is one of those conditions that can have a lot of different causes. Certain medications you’re taking, or a lack of fiber in your diet, are common culprits. But it’s a symptom worth paying close attention to, because it could signal something very serious—including Parkinson’s disease, dementia, or colon cancer. “When the colon becomes cancerous, tumors can form and block the normal flow of stool and prevent stool from passing through which can cause constipation,” explains Williams. “In addition, tumors can interfere with the nerves supplying the muscles causing decreased gut motility causing constipation.” For more health news sent directly to your inbox, sign up for our daily newsletter. “If you notice your poop is black or tarry, it might be due to something as simple as a change in your diet or a new medicine you’re taking,” says WebMD, whose experts note that other causes for black, tarry stools include bleeding ulcers, iron supplements, or medicines that contain bismuth. However, “If you have bleeding in the upper GI tract—the esophagus, stomach, and duodenum—you could have black, tarry stools that are called melena,” they warn. “It could be a sign of esophageal and gastric cancers.” “Diarrhea or constipation can be a sign of pancreatic cancer, because pancreatic cancer can cause the pancreas to produce less pancreatic enzymes than are needed to digest food properly,” warns Williams. Other cancers can cause diarrhea too, according to the Mayo Clinic. “These include neuroendocrine tumors, colon cancer, lymphoma, [and] medullary thyroid cancer.” If you notice other symptoms, including “an inability to control bowel movements; diarrhea accompanied by dizziness; [or] weight loss due to diarrhea,” the Mayo Clinic suggests calling your doctor right away.