Pseudomembranous Colitis with Toxic Megacolon: A Case Report

Pseudomembranous colitis is a condition where the lining of the colon becomes inflamed and irritated due to damage from toxins produced by the pathogenic bacterium Clostridiodes difficile. It’s marked by the appearance of yellowish-white patches, called pseudo membranes, which are made up of dead cells, immune cells, mucus and protein on the inner surface of the colon. These patches form on the surface of the colon as a result of damage caused by toxins from an overgrowth of harmful bacteria, most commonly Clostridioides difficile. ^[1] The main causes of pseudomembranous colitis are antibiotics use, hospitalization or long term care stay, weakened immune system, advanced age, use of proton pump inhibitors (PPIs), surgery or procedures involving the gastrointestinal tract, previous history of Clostridiodes difficile infection (CDI).^[2] The  symptoms of pseudomembranous colitis are severe watery diarrhea, abdominal pain, fever, loss of appetite, tenesmus, mucus or blood in stools, leukocytosis, hypoalbuminemia, fatigue, weakness, dehydration, nausea and vomiting.^[3] Pseudomembranous colitis is usually diagnosed by evaluating patient symptoms, laboratory investigation test for detecting high WBC count and low albumin levels, testing stool samples for C. difficile toxins, through procedures such as colonoscopy and sigmoidoscopy and through CECT scan of abdomen and pelvis.^[4] The complications of Pseudomembranous colitis is toxic megacolon, bowel perforation, protein losing enteropathy, colonic stricture, paralytic ileus,  hypovolemic shock, sepsis and septic shock.^[5] Pseudomembranous Colitis with toxic megacolon  is a severe and dangerous form of C. difficile infection. In this condition, the colon becomes heavily inflamed and develops yellowish-white patches made of mucus, dead cells, and inflammatory debris. At the same time, the colon becomes excessively swollen and loses its ability to move normally (toxic megacolon), which can quickly become life-threatening due to the risk of colon rupture, severe infection, and organ failure.^[6] This condition is managed through stopping unnecessary antibiotics that may  trigger C. difficile, stopping all anti-motility agents like loperamide, opioids they worsen toxic megacolon, strict bowel rest by taking nothing orally, continuous monitoring of vitals, fluid balance and lab parameters, iv fluids resuscitation by correcting dehydration and electrolyte imbalances, use vasopressors if hypotension persists despite fluids.^[7] Antibiotic therapy involves oral or nasogastric tube used as route for administration of vancomycin and iv metronidazole and surgical interventions involves subtotal colectomy with end ileostomy for the conditions like peritonitis, colonic perforation, worsening sepsis or multi organ failure, no improvement on maximal medical therapy within 24-48 hours and persistent massive colonic dilatation (≥10-12 cm), Diverting loop ileostomy with colonic lavage less common surgical technique and is a alternative option in selected patients for the conditions in which the patient is critically ill or very frail who may not tolerate full colectomy, emergency total proctolectomy is a rare surgical procedure involves the complete removal of colon and rectum.^[8] Here we are reporting a case of pseudomembranous colitis with toxic mega colon, which was confirmed by the symptoms, lab parameters and through CECT scan of abdomen and pelvis and through sigmoidoscopy.

CASE PRESENTATION

A 73 year old male patient was admitted to the gastroenterology department with complaints of cough, history of fever, abdominal pain, abdominal distension and excessive fatigue. The patient had  an recent hospitalization for COPD acute exacerbation. The patient had an past medical history of Type II Diabetes Mellitus, Systemic Hypertension and COPD. The patient had an past medication history includes TAB. TELMISARTAN + CILNIIDIPINE, Insulin and Inhaler.

The patient was conscious, oriented, afebrile, chest was clear and heart sounds were normal and GIT was distended. During admission, the patient had an  pulse rate of 94 beats/min, respiratory rate of 24 breaths/min, peripheral capillary oxygen saturation was 88% and the blood pressure was 140/90 mm Hg. The patient’s  laboratory investigation was showed an elevation in  Polymorphs (89%), WBC count (19370 cells/cumm²),Urea (158 mg/dl), Creatinine (1.5 mg/dl), Sodium (129 mEq/L), Potassium (3.1 mEq/L), ESR (85 mm/hr), CRP (52.0 mg/dl), Amylase (141 U/L), Lipase (302 U/L), Trop I (53.7 ng/dl), Procalcitonin (1.65 ng/ ml) , Prostate specific antigen (PSA – 7.08 ng/ml), HbA1C ( 6.9 % )Pus cells (5-16 / hpf ), RBCs (16-18 / hpf) and showed an decline in  Lymphocytes (8.1 %), Sodium (129 mEq/L), Potassium (3.1 mEq/L) and Serum Albumin (2.1 gm/dl).USG chest showed bilateral pleural effusion.

CECT abdomen and pelvis scan was as given in (Figure 1) done for diagnosing pseudomembranous colitis with toxic megacolon  was found out that  edematous bowel wall noted in the ascending colon and descending colon with minimal adjacent fat stranding, normal mucosal enhancement – likely colitis, colonic diverticulosis, mild ascites, atherosclerotic wall thickening in the right distal common iliac artery extending into proximal internal iliac artery causing 70 % luminal narrowing in the right distal common iliac artery and 50 % luminal narrowing in right proximal internal iliac artery.

Figure 1: CECT Scan of abdomen and pelvis

Through Sigmoidoscopy procedure images obtained was as given in (Figure 2) shows that in the rectum, whitish elevated plaque like lesions made up of dead cells that is necrotic epithelial cells, fibrin, mucus, inflammatory cells and cellular debris with edematous surrounding mucosa, pseudo membranes sit on the mucosa of the colon and large hemorrhoids was seen.

Figure 2 :  Sigmoidoscopy images

The patient condition was managed with a combination of IV fluids, intravenous antibiotics, supportive therapy, probiotic supplementation and oral medications .As a part of initial emergency medical care, stat medications was given INJ. MAGNESIUM SULFATE 1gm IV at night time for supporting bowel motility and helps in bronchodilation, INJ. PARACETAMOL 1gm  at night timeIV for abdominal pain and fever, INJ. POLYMYXIN 15 mg IV for, INJ. FUROSEMIDE 20 mg IV for fluid retention and IV fluids RINGER’S LACTATE 250 ml IV,  NORMAL SALINE +POTASSIUM CHLORIDE 500 ml + 50 ml  IV for electrolyte imbalances including hyponatremia, hypokalemia and for fatigue & INJ. ALBUMIN 200 ml IV for hypoalbuminemia.  During the days of hospital stay, the patient was treated with , INJ. MEROPENEM 1 gm IV Q8H, INJ. AZITHROMYCIN 500 mg IV OD INJ. POLYMYXIN 7.5 mg IV BD, & INJ. METRONIDAZOLE 500 mg IV Q8H were administered to manage infection. NEB. IPATROPIUM BROMIDE 250 mg Q6H,NEB. LEVOSALBUTAMOL 0.63 mg Q6H & NEB. FORMOTEROL FUMARATE & BUDESONIDE 20 mcg + 0.5 mcg BD ,CAP. FLUVINAVIR 75 mg BD &TAB. ACETYLCYTSIENE + ACEBROPHYLLINE 600mg + 100 mg P/O BD for obstructive airway disease, TAB. BILASTINE + MONTELUKAST 20 mg + 10 mg P/O HS for allergy,TAB. TOLVAPTAN 15 mg P/O OD for hyponatremia, TAB. MIRABEGRON 50 mg OD for overactive bladder, TAB. DUTASTERIDE 0.5 mg P/O OD for Beningn prostatic hyperplasia, TAB. TORSEMIDE 20 mg P/O OD for fluid retention, SYP. LACTULOSE 30ml P/O BD for constipation, INJ. METHYLPREDNISOLONE 40 mg IV Q6H  for inflammation,  which was later tapered and discontinued.INJ PANTOPRAZOLE 40 mg IV OD for gastric irritation and later shifted to TAB. PANTOPRAZOLE 40 mg P/O BD and  was treated with probiotic supplementation CAP. ECONORM (SACCHAROMYCES BOULARDII )250 mg P/O OD for improving gastrointestinal symptoms and for digestion.

DISCUSSION

Pseudomembranous colitis (PMC) is an acute inflammatory condition of the colon, most commonly caused by Clostridioides difficile infection following antibiotic use, leading to the formation of yellow-white pseudomembranes on the colonic mucosa. In severe cases, it can progress to toxic megacolon, a life-threatening complication characterized by colonic dilatation, systemic toxicity, fever, abdominal pain, distension, and altered bowel habits. Diagnosis involves clinical suspicion supported by imaging (such as abdominal X-ray or CT showing colonic dilatation), endoscopic findings, and positive stool assays for C. difficile toxins. Early and aggressive management is critical, including bowel rest, intravenous fluids, electrolyte correction, and targeted antibiotic therapy with oral vancomycin and/or IV metronidazole; surgical intervention may be required in cases unresponsive to medical therapy or with signs of perforation or peritonitis.

Table 1. comparative summary of  3 reported cases of pseudomembranous colitis with toxic megacolon with our case