Patients with colitis present with abdominal pain, watery diarrhea, fever, urgency, and blood in the stool. Examining doctor should look for red flags such as patient’s age, hemodynamic changes, nocturnal diarrheas, tenesmus, urgency, weight loss, comorbidities, history of heart failure, arrhythmias, autoimmune disorders, detailed history of patient’s medication, signs suggestive of toxic megacolon, and anemia.

In ulcerative colitis, extraintestinal manifestations associated with colitis and disease activity include arthropathies, eye changes (episcleritis, scleritis, uveitis), skin changes (erythema nodosum and pyoderma gangrenosum). Other extraintestinal manifestations reported in colitis include sacroiliitis, ankylosing spondylitis, hepatic dysfunction, and primary sclerosing cholangitis.[6]

Diagnosis of colitis has its basis in clinical findings, laboratory tests, endoscopy, and biopsy. Endoscopy and biopsy should not be the primary investigations and may be arranged after a critical evaluation of the patient’s condition and the results from the initial examinations.

• Because colonic infection is a common etiology of colitis and can produce clinical presentations indistinguishable from inflammatory bowel disease, microbiological studies and cultures for bacterial and parasitic infestations should be the primary investigations. Laboratory workup including complete blood count, ESR, CRP, arterial blood gases, activated partial thromboplastin time, serum albumin, total protein, blood urea, creatinine, electrolytes, and purified protein derivative, should be ordered.
• D-lactate levels in the blood could be a sensitive marker of colonic ischemia; however, it is an experimental laboratory test.
• Electrocardiogram, transthoracic and even Holter monitoring may be necessary in patients with ischemic colitis.
• Plain X-ray is of limited value; however, it may be useful in the diagnosis of toxic megacolon, bowel obstruction, and intestinal perforation (pneumoperitoneum). Thumbprinting is a classic finding for mucosal edema though not specific for ischemic colitis.
• Multidetector CT and thin sections, can accurately demonstrate inflammatory changes in the colonic wall and help assess the extent of disease. Ulcerative colitis is distinguishable from granulomatous colitis (Crohn disease) in terms of location of involvement, extent, and appearance of colonic wall thickening, and type of complications.
• Colonoscopy or proctosigmoidoscopy is essential for the final diagnosis; it typically appears normal in microscopic colitis although edema or erythema may present. Ulceration suggests an alternative diagnosis, although these can be present in patients on non-steroidal anti-inflammatory drugs.
• Other colonoscopy changes, depending on the etiology, include loss of typical vascular pattern, granularity, friability, and ulceration. 
• Several laboratory tests specific to certain colitis may be ordered including perinuclear antineutrophil cytoplasmic antibodies (P-ANCA), which may present in Crohn disease, anti-saccharomyces cerevisiae antibodies (ASCA), a feature in both ulcerative colitis and Crohn disease, and carcinoembryonic antigen (CEA), which is elevated in patients with active ulcerative colitis.[6]
• Assess the extent, degree, and severity of the disease and any complications.

Not all infectious colitis requires antibiotic therapy; patients with mild to moderate C. jejuni or Salmonella infections do not need antibiotic therapy because the infection is self-limited. Treatment with quinolinic acid antibiotics is reserved for patients with dysentery and high fever suggestive of bacteremia. Also, patients with AIDS, malignancy, transplantation, prosthetic implants, valvular heart disease or extreme age will require antibiotic therapy. For mild to moderate cases of C. difficile infection metronidazole is the preferred treatment. In severe cases of C. difficile infection oral vancomycin is recommended. In complicated cases, oral vancomycin with intravenous metronidazole is recommended. Cytomegalovirus colitis is treated with valganciclovir; the duration of treatment should be individualized depending on the clinical picture and laboratory parameters.[11]

5-aminosalicylic acid (5-ASA) drugs are the standard treatment in ulcerative colitis for induction and maintenance of remission of mild and moderate cases. The place of 5-ASA in the management of Crohn disease is controversial. Immunomodulators including azathioprine, 6-mercaptopurine, and methotrexate, are the mainstay of treatment in maintenance therapy for patients with mild to moderately severe Crohn disease and frequently relapsing ulcerative colitis where 5-ASA drugs failed. Biological therapies, tumor necrosis factor-oe, such as infliximab, adalimumab, and certolizumab are available for the management of Crohn disease, to get the disease under control and long-term maintenance. Corticosteroids are effective in reducing remission in inflammatory bowel disease and are cheap. However, they are not recommended for maintenance therapy and are associated with serious side effects. Surgery is recommended in patients not responding to medical therapy.[6][12][13]

In microscopic colitis, discontinuation of any offending medication and smoking cessation are vital. While anti-diarrheal medications, bismuth subsalicylate or cholestyramine may help, budesonide is effective in inducing remission and should be the first medication to start.[14] Patients in whom budesonide therapy is not feasible, bismuth salicylate or mesalamine is an option.

Patients with ischemic colitis without peritoneal signs, medical management may be safely employed including intravenous fluid resuscitation, optimizing cardiac output, use of supplementation of oxygen, placing the bowel on rest, parenteral nutrition, the use of broad-spectrum antibiotics to cover both aerobic and anaerobic coliform bacteria and close monitoring. Failure of medical management and the development of peritoneal signs or intestinal perforation necessitates surgical intervention and bowel resection.[10][15]

Anti-tuberculous treatment comprising isoniazid, rifampin, pyrazinamide, and ethambutol for 2 months is recommended in tuberculous colitis followed by isoniazid and rifampin for 7 months. The duration of treatment is nine months, and patients should be regularly followed up for assessing their response to the treatment.[16]

• Irritable bowel syndrome
• Celiac disease (patients with celiac disease who have continued to have watery motions despite being on a strict gluten-free diet should be investigated for microscopic colitis)
• Colorectal cancer
• Diverticulitis
• Toxic megacolon
• Viral/bacterial gastroenteritis
• Other types of colitis

Complications include:

• Intestinal perforation
• Bowel strictures, fistulas, abscess, and intestinal obstruction
• Fecal incontinence
• Pelvic abscess
• Enterocutaneous fistulas, particularly in Crohn disease
• Pouchitis
• Guillain-Barre syndrome (Campylobacter jejuni colitis, cytomegalovirus colitis, and reported in ulcerative colitis)
• Hemolytic uremic syndrome (enterohemorrhagic E coli, Shigella)
• Encephalopathy, seizures (Shigella)

Toxic megacolon is an uncommon complication of colitis, characterized by total or segmental nonobstructive colonic dilatation, associated with systemic toxicity and has an overall mortality of 19%.[17] Diseases such as ulcerative colitis and pseudomembranous colitis are well-known to be complicated and develop toxic megacolon for over 60% of cases.[18] Other conditions associated with inflammation of colon including Campylobacter and shigella colitis may develop toxic megacolon.

The symptoms of colitis are non-specific, detailed medical, examination and laboratory workup are needed; however, endoscopic evaluation and mucosal biopsy are essential to confirm the diagnosis and exclude inflammatory bowel disease-associated colitis.

Colitis, depending on its cause, may be self-limited, life-threatening, chronic or recurrent. Patients with chronic and recurrent colitis need lifelong monitoring. The general practitioners have key roles in early diagnosis of the disease, support of the patients and assisting them with smoking cessation and management of their disease. The patients should be encouraged by nursing to take responsibility for their condition and provide knowledge of their pathology and drugs used. The pharmacists should be aware of the disease and drugs that could cause colitis and assist in explaining the potential complications. The nurse and pharmacist should report untoward complications to the clinical team. Other healthcare professionals including nurses need to be mindful of the clinical picture, common presentations, management, and care of patients with chronic and recurrent colitis. The surgeons play a key role with specific aspects of colitis in emergencies and in cases that failed to respond to medical therapy. Patients with chronic colitis develop depression and anxiety and need mental health support. All these various disciplines need to work together collaboratively in an interprofessional team to bring about the best outcomes for patients who have colitis. [Level V]