Ulcerative Colitis Treatment: How to Calm Flares and When Bleeding Needs Urgent Care
A flare of ulcerative colitis (UC) can come on over days or weeks. It brings more trips to the bathroom, blood in the stool, cramping and an urgent need to go that is hard to ignore. Ulcerative colitis treatment has grown a lot in recent years, and many flares can be brought under control with the right plan. Knowing your options, and knowing which symptoms can’t wait, puts you in a better position to act quickly.
What happens during a UC flare
Ulcerative colitis is a type of inflammatory bowel disease (IBD) that causes inflammation and sores in the lining of the large intestine (colon). It usually starts in the rectum and can spread upward through part or all of the colon. Symptoms tend to come and go, with flares separated by periods of remission.
Common flare symptoms, as described by the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), include:
- Diarrhea, often with blood, mucus or pus
- Cramping and belly pain
- An urgent need to have a bowel movement
- A constant feeling that you need to go even when your bowel is empty (tenesmus)
With more severe disease, people may also have fatigue, fever, nausea or vomiting, and weight loss. NIDDK describes severe symptoms as more than six bowel movements a day, with blood in the stool most of the time.
Colitis, ulcerative colitis and what causes them
Colitis simply means inflammation of the colon, and ulcerative colitis is only one cause of it. MedlinePlus lists several others, including infections from viruses, bacteria or parasites, Crohn’s disease and C. diff infection. Reduced blood flow to the colon (ischemic colitis) and past radiation treatment can cause it too. Colitis symptoms overlap a lot across these conditions, so testing matters before anyone settles on a diagnosis.
Those shared symptoms include belly pain and bloating that may come and go, diarrhea, bloody stools and a constant urge to have a bowel movement. Some people also have a fever or become dehydrated. With ulcerative colitis, the symptoms keep returning over months and years instead of clearing up after a single illness.
Nobody knows exactly what causes ulcerative colitis. NIDDK points to a mix of factors, including certain genes, an abnormal reaction of the immune system and differences in gut bacteria. Researchers are still studying how outside factors in a person’s surroundings play a part. MedlinePlus notes that stress and certain foods can trigger symptoms, but they do not cause the disease.
First step: rule out other causes
Not every flare is the disease itself, because infections can look exactly like a UC flare or set one off. For that reason, the American College of Gastroenterology (ACG) recommends stool testing for C. diff (Clostridioides difficile), a bacterial infection of the colon. Your gastroenterologist may also order blood tests and a stool test called fecal calprotectin, which measures inflammation in the bowel.
The ACG recommends calprotectin to check how well treatment is working and to look into a suspected relapse. A flexible sigmoidoscopy or colonoscopy lets your doctor see the lining directly and take biopsies if needed. Be sure to tell your doctor about any pain relievers you use. NIDDK advises people with UC to avoid NSAIDs such as ibuprofen and naproxen because they can make symptoms worse.
Ulcerative colitis treatment for mild to moderate flares
Treatment depends on how severe the flare is and how much of the colon is involved. Aminosalicylates (5-ASA), such as mesalamine, are the usual starting point for mild to moderate UC. They come as pills and as rectal forms (suppositories or enemas).
When inflammation is limited to the rectum or the lower colon, rectal treatment puts medicine right where it’s needed. The ACG recommends this approach for these patients. Many people use oral and rectal forms together.
Budesonide, a steroid that acts mainly in the gut, may be added if 5-ASA alone isn’t enough. Your gastroenterologist will check within several weeks whether the first treatment is working, so a plan that isn’t helping can be changed sooner.
Treatment for moderate to severe flares
Corticosteroids such as prednisone can calm a moderate to severe flare quickly, but they are meant for short-term use. Both NIDDK and the ACG note that steroids should not be used to keep UC in remission, because long-term use carries serious side effects. Never stop prednisone or another steroid suddenly on your own, because the dose has to be lowered slowly on a schedule your doctor sets.
Advanced therapies have changed UC care in recent years. Biologics are lab-made antibodies, given by infusion or injection, that block specific parts of the immune response. Small-molecule medicines are pills that work on immune signaling inside cells. The American Gastroenterological Association’s (AGA) 2024 living guideline supports using these more effective medicines earlier for moderate to severe UC. That means not waiting until several older options have failed.
The ACG notes that response rates are higher when an advanced therapy is the first one a person tries. Current guidelines aim for healing of the colon lining seen on endoscopy, not only symptom relief. Healing is linked to fewer flares, hospital stays and surgeries over time.
Severe flares and hospital care
Some flares are too severe to manage at home. In the hospital, care usually starts with testing to rule out infection, including C. diff. It also includes steroids given through an IV and a flexible sigmoidoscopy to judge how severe the flare is and take biopsies.
Patients usually get medicine to prevent blood clots as well, since clots are more likely during a severe flare. If a severe flare isn’t responding well to IV steroids after about three to five days, the ACG recommends a rescue medicine given by IV. Surgery is the next option if medicines fail, and a colorectal surgeon is often involved early.
Surgery to remove the colon is an option when medicines don’t work or when complications develop, and NIDDK describes two main approaches. One creates an internal pouch from the end of the small intestine (ileoanal reservoir surgery). The other brings the small intestine to an opening on the belly (ileostomy).
How to stop ulcerative colitis bleeding
Bleeding in UC comes from the inflamed, sore lining of the colon and rectum. The way to stop ulcerative colitis bleeding is to calm that inflammation, using the treatments described above. No home remedy seals the sores on its own. When bleeding comes mostly from the rectum or lower colon, rectal forms of 5-ASA put medicine right on the inflamed area, which is why the ACG recommends them for this kind of disease.
A few steps help while treatment takes hold. Skip NSAIDs such as ibuprofen and naproxen, since NIDDK says they can make UC symptoms worse, and ask your doctor whether acetaminophen is a better choice for mild pain. Keep a short daily record of how many bowel movements you have, how much blood you see and how urgent they feel. That record gives your gastroenterologist a clear picture of whether the plan is working.
Ongoing blood loss can lead to anemia, which means a low red blood cell count. MedlinePlus lists anemia among the complications of repeated severe flares, so your doctor may check your blood count during a flare. For severe anemia, NIDDK notes that doctors may give a blood transfusion. MedlinePlus also lists new or increased bleeding as a reason to contact your provider, even when it doesn’t reach the emergency signs listed further down.
Eating and daily habits during a flare
Food does not cause ulcerative colitis, but what you eat can change how you feel during a flare. There is no single colitis diet that works for everyone. MedlinePlus offers practical tips for flare days. Eat small amounts of food throughout the day, and drink plenty of water in small amounts spread across the day.
During a flare, MedlinePlus suggests avoiding high-fiber foods such as bran, beans, nuts, seeds and popcorn. It also suggests avoiding fatty, greasy or fried foods and sauces made with butter, margarine or heavy cream. If you are lactose intolerant, limit milk products. As symptoms settle, ask your care team when to bring higher-fiber foods back into your meals.
If flares make it hard to eat enough, or you are losing weight, ask about seeing a registered dietitian. A dietitian can help you keep meals predictable without cutting out more foods than you need to. Stress can bring on symptoms as well, and MedlinePlus suggests asking your provider for tips on managing it.
Staying in remission after a flare
Once a flare calms down, the goal shifts to keeping it from coming back. NIDDK explains that medicines are used both to bring on remission and to maintain it, and that immunosuppressants can also help people stay in remission. Steroids are not used for this, so your doctor will plan a slow taper and a longer-term medicine instead. Keep taking your maintenance medicine even when you feel well, unless your doctor tells you otherwise.
Long-standing UC also raises the risk of colon cancer. MedlinePlus notes that this risk goes up with each decade after diagnosis, so your gastroenterologist will recommend a colonoscopy at regular intervals to check for it. These exams look for early changes in the lining and also show how well your colon has healed. The right schedule depends on your own history, so ask which interval applies to you.
When bleeding needs urgent care
Some blood in the stool is common during a UC flare, but certain signs mean you need care the same day.
Go to the emergency room or call 911 if you have:
- Heavy rectal bleeding, or passing large clots
- Black, tarry stools
- Dizziness, fainting or a racing heartbeat
- Severe belly pain, or a belly that becomes swollen and hard
- A high fever along with bloody diarrhea
- Vomiting that keeps you from holding down fluids
These can be signs of serious blood loss, a severe flare or complications such as toxic megacolon (dangerous widening of the colon) or a tear in the bowel wall. Call your gastroenterologist the same day if you’re having more than six bloody bowel movements a day, if symptoms are getting worse despite treatment, or if you notice signs of dehydration such as very little urine.
When to see a gastroenterologist
Make an appointment with a gastroenterologist if you have any of these:
- Diarrhea with blood or mucus that lasts more than a few days
- An urgent need to go, or bowel movements that wake you at night
- A diagnosis of UC and symptoms that keep coming back
- Ongoing steroid use to control symptoms
- Weight loss or fatigue along with bowel changes
GI Associates diagnoses and treats ulcerative colitis at its clinics in Wausau, Stevens Point and Wisconsin Rapids, including colonoscopy and long-term follow-up care. If you want a fresh look at your treatment plan, request an appointment between flares or during one.
This article is for general education and is not a substitute for medical advice. Seek emergency care for heavy bleeding, black or tarry stools, fainting or severe belly pain. Talk with your doctor before stopping or changing any medicine.
Sources
- Rubin DT, Ananthakrishnan AN, Siegel CA, Barnes EL, Long MD. ACG Clinical Guideline Update: Ulcerative Colitis in Adults. American Journal of Gastroenterology. 2025;120(6):1187-1224. https://pubmed.ncbi.nlm.nih.gov/40701556/
- Singh S, Loftus EV Jr, Limketkai BN, et al. AGA Living Clinical Practice Guideline on Pharmacological Management of Moderate-to-Severe Ulcerative Colitis. Gastroenterology. 2024;167(7):1307-1343. https://pubmed.ncbi.nlm.nih.gov/39572132/
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Treatment for Ulcerative Colitis. https://www.niddk.nih.gov/health-information/digestive-diseases/ulcerative-colitis/treatment
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Symptoms and Causes of Ulcerative Colitis. https://www.niddk.nih.gov/health-information/digestive-diseases/ulcerative-colitis/symptoms-causes
- MedlinePlus Medical Encyclopedia (U.S. National Library of Medicine). Ulcerative colitis. https://medlineplus.gov/ency/article/000250.htm
- MedlinePlus Medical Encyclopedia (U.S. National Library of Medicine). Colitis. https://medlineplus.gov/ency/article/001125.htm